Bike fit calculator results explained: read all nine outputs
Read one complete fictional bike-fit calculation: saddle height, setback, drop, frame reach, crank length, widths, cleat position and the separate knee-angle reference. Keep app estimates, declared settings and real measurements apart.
Published 23 October 2026 · OpenBikeFit
Nine outputs. No bicycle measured.
Declared inputs and a profile go through software rules and rounding. The nine result items are estimates or reference bands. A separate physical bicycle reading and a recorded movement observation are different evidence, not automatic verification of this model.
On this page
- 01Read one complete fictional calculator result
- 02Check the input record before interpreting a result
- 03Separate a range, a displayed value and a current-setting difference
- 04Saddle height: distinguish historical ratios from the app approximation
- 05Knee angle: the reference is not a predicted or observed angle
- 06Saddle setback: name the saddle nose and bottom-bracket axis
- 07Drop and reach: do not turn reference bands into a stem order
- 08Frame geometry: the millimetre band is reach, not a frame size
- 09Crank length: a model table and a declared component are different records
- 10Two widths: do not confuse shoulder input, bar outline and saddle support
- 11Cleat position: a reference point is not a bolt-hole coordinate
- 12Missing inputs, labels and comparisons: retain the provenance
- 13Choose a next step that preserves what you actually know
Keep observations separate
Read the blank bicycle record
A blank paper preview, not a calculated setup, saved fit or professional fitting report.
Open toolA bike fit calculator result is a set of model outputs, not a measurement of the bicycle in front of you. Before interpreting a millimetre value, identify the item, the supplied inputs, the physical reference it names and the rule that produced it. A result can be arithmetically reproducible while leaving the real installed position, component permissions and rider movement unobserved. This guide explains the current OpenBikeFit calculator, not every provider that uses the words bike fit.
Start by reading the complete fictional ledger below. No person was measured and no bicycle was adjusted to produce it. All body dimensions, current settings and profile choices are invented declarations. The example is not an ideal body-size pairing, a recommendation for someone with similar measurements, or a saved result to continue. You do not need to enter measurements, create a fit, grant camera permission or upload anything to read it.
Read one complete fictional calculator result
The ledger uses one input set throughout and retains all nine output items, rather than selecting only the numbers that look persuasive. App band names the displayed minimum and maximum; App displayed value names the separately rounded central value. Read the accompanying meaning and missing observation for every row. The final comparison deliberately omits optional entries to show how the source of a number can change.
Fictional software example · not your result
One fixed input set supplies every row below. These are invented declarations, not measurements of a rider or bicycle. Nothing is entered into another tool for you.
- Body lengths
- Height 178 cm; cycling inseam 82 cm; shoulders 40 cm
- Other optional entries
- Sit bones 120 mm; EU shoe size 42
- Selected profile
- Road; Ride regularly; Balanced; Moderate flexibility
- Declared current bicycle
- Saddle 720 mm; crank 172.5 mm — declarations, not inspected measurements
1. Saddle height
- App band
- 717–728 mm
- App displayed value
- 723 mm
App approximation using declared inseam, crank and selected band. Raw LeMond: 724.06 mm; converted Hamley: 721.30 mm. Displayed difference: +3 mm from the fictional declared 720 mm.
No installed saddle point or actual knee angle was measured. +3 mm is subtraction, not an adjustment instruction.
Read the named measurement reference →2. Knee-angle reference
- App band
- 32–38 °
- App displayed value
- 35 °
The app selects a static 27–33° band and adds its fixed 5° convention to display 32–38° dynamically. The central displayed value is 35°.
This is not a prediction of a knee angle, a camera observation or a universal instrument conversion.
Read the named measurement reference →3. Saddle setback
- App band
- 49–75 mm
- App displayed value
- 62 mm
A software band for saddle-nose horizontal setback behind the bottom-bracket axis, scaled from inseam and riding category.
Neither rail position, pelvis position, seatpost offset nor a permitted movement was inspected.
Read the named measurement reference →4. Saddle-to-bar drop
- App band
- 20–60 mm
- App displayed value
- 40 mm
The selected app profile gives a positive drop: the named bar top is lower than the named saddle top. It also names a separate trunk reference of 35–43°.
No bar coordinate, stem length, hood location, trunk angle or sustainable posture was measured.
Read the named measurement reference →5. Frame reach and stack/reach
- App band
- 373–393 mm
- App displayed value
- 383 mm
The numerical band is FRAME REACH, not stack or saddle-to-hand reach. The separate stack/reach reference is 1.50–1.60, a ratio without units.
No frame model, nominal size, contact-point fit, complete stack value or purchase suitability was established.
Read the named measurement reference →6. Crank length
- App band
- 165–170 mm
- App displayed value
- 167.5 mm
The app inseam table gives this band and its 2.5 mm-step displayed value. The declared crank is 172.5 mm; the displayed difference is −5 mm.
A table entry is not a measured crank, compatible replacement, power result or automatic saddle correction.
Read the named measurement reference →7. Handlebar width
- App band
- 380–420 mm
- App displayed value
- 400 mm
The fictional 40 cm shoulder entry supplies 400 mm before the app road-width band. The result uses a named centre-to-centre hood station.
It is not outside width, drop-end width, grip span or proof of support, comfort or mounting permission.
Read the named measurement reference →8. Saddle width
- App band
- 135–150 mm
- App displayed value
- 145 mm
The declared 120 mm sit-bone spacing receives the app 15–30 mm allowance. The central display is rounded to a 5 mm step.
No anatomical accuracy, loaded contact area, pressure, saddle shape or personal saddle choice was established.
Read the named measurement reference →9. Cleat-position reference
- App band
- 0–10 mm
- App displayed value
- 5 mm
MTP1, the first metatarsophalangeal joint behind the big toe, is the named reference relative to the pedal spindle. Shoe size 42 does not narrow this 0–10 mm app convention.
The value is not a shoe-hole coordinate, millimetres to slide a cleat, rotational float, bolt length or assembly permission.
Read the named measurement reference →
Check the input record before interpreting a result
Height and cycling inseam are separate body lengths. Shoulder width is another optional body length, while sit-bone spacing, current saddle height and current crank length use millimetres in the marked fields. Shoe size is a size label, not a millimetre measurement. Selecting inches for the body fields does not silently turn every bicycle value or output into inches. Keep the field label beside the original declaration when reconstructing a calculation.
The profile choices also matter: riding category, experience, selected goal and the declared flexibility category select software rules. They are not observations that the app made about a rider. The example chooses Road, Ride regularly, Balanced and Moderate flexibility. Changing one of those choices can change a result without any body or bicycle changing. A category name such as Balanced does not establish a physical optimum or a professionally assessed capability.
Separate a range, a displayed value and a current-setting difference
A numerical band is the interval selected by this software. Its central displayed value may use a different rounding step from another item: crank length uses a 2.5 mm step, while this saddle-width display uses a 5 mm step. Do not count those decimal places as evidence of measurement accuracy. The edge of a band is not a mechanical limit, and membership in a band does not certify fit, comfort, health or performance.
For the fictional saddle, the app displays 723 mm and the declared current value is 720 mm. The displayed difference is +3 mm. That arithmetic does not verify the current measurement, choose a saddle endpoint, inspect insertion limits or instruct a 3 mm move. If the current value is absent, the difference is unavailable, not zero. Keep the calculation and any physical reading as separate labelled records, even when their numbers happen to agree.
Saddle height: distinguish historical ratios from the app approximation
The declared inseam is 82 cm, or 820 mm. The raw historical ratio is 0.883 × 820 = 724.06 mm. The separate Hamley conversion shown by this app is 1.09 × 820 − 172.5 = 721.30 mm, using the fictional declared crank. These labels refer to different original endpoint conventions; the software conversion is not a tape measurement. Their disagreement is not resolved by averaging them into a supposedly more accurate personal setting.
The app approximation begins with 724.06 + (175 − 172.5) − 4 = 722.56 mm. Its selected static band arguments are 27° and 33° here. The coefficient is 0.0022 × 820 = 1.804 mm per argument degree, giving the unrounded interval 717.148–727.972 mm. Display rounding produces 717–728 mm and the central 723 mm. This calculation explains the software output; it does not derive an actual knee angle, measure a pedal/shoe stack or validate the coefficient for an individual.
The public methodology distinguishes historical reference identities, source-reading limits and these app-specific terms. A book catalog entry is not an inspection of its calculation pages, and a paper about measured knee angles does not establish this inseam-to-height approximation. Keep the source audit attached to the result. Use the separate saddle-point guide to name a real measurement endpoint; do not rename a floor measurement, vertical coordinate or rail position as the same length.
Knee angle: the reference is not a predicted or observed angle
The knee item does not report what the fictional rider actually does. The app selects a 27–33° static band for the example profile and applies its fixed +5° convention to label a dynamic 32–38° band. Its central displayed 35° is still a reference value. No measured knee angle, femur length, shank length, riding event or camera frame was supplied to produce it. The saddle-height argument and this displayed reference must not be mistaken for an independent motion measurement.
A projected phone angle, static goniometer reading and calibrated three-dimensional measurement have their own landmarks and protocols. A numerical conversion between angle labels changes the convention, not the observation. Read the angle-convention guide before comparing such records. An observed angle falling inside an app reference is not installation permission, a diagnosis or proof of a riding benefit. The separate video-report example explains recorded movement; this calculator ledger does not replace it.
Saddle setback: name the saddle nose and bottom-bracket axis
For this road example, the app starts with 820 × 0.08 = 65.6 mm and selects its rounded road band of 49–75 mm, with a central 62 mm. That is a software scaling convention for a named horizontal saddle-nose setback. It is not a measured knee-over-pedal position, a rail mark or an observed pelvis location. The word setback is used for several different dimensions, so preserve the endpoint instead of copying the bare number.
A seatpost head offset and the saddle nose position relative to the bottom bracket are not interchangeable. Saddle shape, rail position, tilt and the named top point can change the physical record. A band cannot determine whether a clamp supports a particular rail station. Record the current bicycle separately, retain its exact reference and obtain the appropriate hardware information before considering any physical work. This reading example does not loosen, reposition or approve a component.
Drop and reach: do not turn reference bands into a stem order
The example profile selects a 20–60 mm saddle-to-bar drop band with a central 40 mm. Positive drop means the named bar top is below the named saddle top; a negative drop would mean it is above. This is a height difference, not a handlebar shape dimension called drop. Nor is it the height of the hoods, a stem angle, a spacer stack or a measured torso angle. The separately stated 35–43° trunk reference is another app convention.
Moving a real bar clamp depends on the actual head angle, stem, spacers and receiving assembly, while hand contact depends on more geometry beyond the clamp. Subtracting an existing drop from a model band does not select a replacement part or a permitted installation. The existing cockpit and measurement guides define those narrower tasks. Keep their real baselines and physical checks separate rather than inventing a complete cockpit from one calculated difference.
Frame geometry: the millimetre band is reach, not a frame size
The frame item displays 373–393 mm with a central 383 mm. Those are frame-reach values from the current height/inseam/profile heuristic. The accompanying 1.50–1.60 stack/reach reference is a dimensionless ratio, not another millimetre length. No actual frame chart, completed cockpit or saddle-to-hand distance was supplied. The item does not mean that a frame with a particular commercial size label has been selected or inspected.
Do not read 383 mm as stack, top-tube length, stem length or hand reach. A manufacturer chart may describe a frame endpoint while a fit record names a bar clamp or hood. Even multiplying a ratio by a number would only perform conditional arithmetic, not identify a real bicycle or a permitted build. Use the separate frame-reference guides and comparator with actual, matching endpoints when that is your task; this article does not approve a purchase.
Crank length: a model table and a declared component are different records
The app inseam table gives 165–170 mm and displays 167.5 mm for this example. The declared current crank remains 172.5 mm, so the displayed difference is −5 mm. The first number is model-selected; the second is a fictional declaration. The table does not inspect a crank stamp, pedal axis, spindle interface, chainline or clearance. It does not establish an individual best length or a guaranteed power, comfort or health outcome.
Changing the declared current crank can also change the saddle-height approximation because that same declaration is one of its inputs. This numerical dependency is not proof that replacing hardware requires the calculator’s entire predicted correction. A real comparison needs the correct physical endpoints and the relevant component system. Read the crank and saddle-reference guides separately; do not combine the ledger into a shopping list or an automatic sequence of adjustments.
Two widths: do not confuse shoulder input, bar outline and saddle support
The fictional 40 cm shoulder entry produces the app road bar band of 380–420 mm and central 400 mm. That reference names centre-to-centre width at the hoods. A manufacturer may specify another station or an outside dimension, and a flared bar may have different hood and drop spans. Numerical similarity does not make those dimensions interchangeable. The calculator did not measure the installed bar, hand span, contact comfort or breathing.
The separate saddle-width item starts with declared sit-bone spacing of 120 mm and adds the app allowance of 15–30 mm, producing 135–150 mm and a rounded central 145 mm. It does not observe anatomy, pressure distribution, loaded contact area or saddle shape. Outside product width and usable support at a named station are different quantities. If sit-bone spacing was not entered, this item is unavailable; the software has not measured a zero-width pelvis or selected an alternative saddle.
Cleat position: a reference point is not a bolt-hole coordinate
The cleat item retains the app 0–10 mm convention with a central 5 mm. Its named reference is the first metatarsophalangeal joint, MTP1, relative to the pedal spindle. The entered EU shoe size does not narrow that band in the current implementation. A zero boundary here is a deliberate reference value inside a convention, unlike an absent measurement. Neither value specifies how far to slide a particular cleat on a particular shoe.
Cleat fore-aft position, mounted rotation, available float, pedal engagement and fastening hardware are separate questions. A generic reference cannot identify an exact cleat/pedal generation or authorize a bolt length or mounting arrangement. Read the compatibility and float guides for those distinctions and preserve the existing physical setup before any separately justified work. This explanatory example does not diagnose a symptom, assign a movement cause or certify an assembly.
Missing inputs, labels and comparisons: retain the provenance
The omitted-input comparison in the ledger is intentional. Without a declared current crank, the app substitutes a model crank term; without shoulders, bar width is estimated from height; without sit-bone spacing, saddle width is unavailable. A coincidentally unchanged bar number still has a different origin. Do not replace blanks with zero just to obtain a fully populated report. Do not hide the optional declarations when sharing an interpretation of the result.
Source-type and confidence labels describe software evidence or input completeness, not a personal accuracy percentage or a statistical confidence interval. Opening a citation does not establish that it validates every associated app rule. Comparing two saved sets of calculator inputs compares calculations; it is not automatically a before-and-after physical experiment. Keep the changed inputs visible and separate from a later independent bicycle reading or recorded movement observation.
Choose a next step that preserves what you actually know
If you want to reconstruct your own calculation, first check the original field units and selected profile, then deliberately use the separate calculator. The reading link does not populate it with this fiction. If you want to document an installed bicycle instead, start with the blank worksheet and name the real measurement references. A static model output should not be entered as an observed installed setting merely because both fields use millimetres.
The result-link review is another separate action. A link contains declared inputs that are recalculated by the available software, not a frozen professional report or a complete camera backup. Body dimensions and technical records may identify a person; local processing does not make an external copy anonymous. This guide sends no entered values or record IDs in its links. Ordinary navigation still makes web requests, and deliberately opened tools retain their existing access and privacy boundaries.
Keep your conclusion as specific as the evidence: a software rule was evaluated from declared inputs; a physical point was independently measured; or movement was estimated from a recording under its protocol. Those statements can coexist without pretending they are the same observation. When the required hardware reference, physical information or professional scope is missing, preserve the unresolved question. A more complete explanation is useful; a more authoritative-looking unsupported verdict is not.
Practical questions
Frequently asked questions
Does the calculator measure nine parts of my bicycle?
No. It produces nine software result items from declared inputs and selected categories. It does not inspect the bicycle or observe pedalling. An estimated length, a selected reference band and an actual installed measurement are different records.
Should I move my saddle by the displayed current-setting difference?
The difference is calculated minus declared, not installation permission. Check whether a real current reading has matching endpoints and conditions, retain it separately, and identify the relevant component requirements before any separately justified physical work.
Why does saddle height change when I leave current crank length blank?
The current implementation uses a declared crank if present and otherwise an estimate from its own crank band. Omitting the declaration changes a model input. The fictional example shows the resulting different output; no bicycle moved and no actual correction was measured.
Is the displayed knee angle predicted from my height and inseam?
No. It is a selected reference band, with an app-specific static-to-dynamic convention. No measured knee angle or individual segment lengths were supplied. A phone observation, static goniometer reading and three-dimensional protocol cannot be silently substituted.
Why is there no saddle-width result without sit-bone spacing?
The current rule needs that optional declaration. Without it, this item is unavailable rather than zero or an automatic alternative. Even with a declaration, the app allowance does not measure anatomy, contact area, pressure or the suitability of a saddle.
Does frame reach tell me the exact bicycle size to buy?
No. The millimetre result is a frame-reach heuristic and its separate stack/reach reference is a ratio without units. They do not identify an actual frame model, complete contact coordinates, compatibility or purchase suitability.
Can I compare two calculator results as a before-and-after fit?
You can compare calculations while retaining their different inputs and software context. That does not establish an independently measured physical change, its cause or a benefit. Record real bicycle coordinates and movement observations separately under matching protocols.
Can I read this example without entering measurements or starting a camera?
Yes. The public guide and its numerical ledger are fixed fictional reading material. Reading creates no fit and starts no calculation, save, recording or upload. Separate tool links require your deliberate action and keep their existing access and privacy boundaries.