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THE FIT WORKBENCH

E-bike frame size and fit calculator

Updated

By · Research and corrections policy

Use your height and inseam to compare dated manufacturer ranges. Start with a published size, then check reach, mounting and control on the actual bike. This adult planning tool does not approve a fit or select an unverified model.

Short answer

Start e-bike sizing with barefoot height and body inseam, then compare the exact manufacturer configuration. A chart match does not establish comfortable reach, saddle adjustment or mounting. This calculator compares dated published ranges and offers Gazelle’s brand-specific frame-size arithmetic; missing measurements remain unknown. Confirm the final fit on a test ride.

Measure barefoot height from floor to head and inseam from floor to a level book between the legs; compare the exact size chart and test ride.
Body measurements narrow the questions. They do not certify a fit or replace the exact model's instructions.

1 · Measure barefoot height

Stand straight against a wall; measure floor to the top of your head.

2 · Measure body inseam

Measure floor to the top of a level book held snugly between your legs.

3 · Compare, then test

Use the exact configuration chart, then check reach, adjustment, mounting and control.

Illustrative default: height 170 cm, inseam 80 cm. No personal measurement is stored. A matching range is a starting point for a test ride.

1 · Your measurements

Measure barefoot. Height is floor to the top of your head, standing straight against a wall. For inseam, hold a level book or ruler snugly between your legs and measure its top edge to the floor. This is body inseam, not trouser length.

2 · What do you want to compare?

Frame form is a test-ride question, not an inferred medical need or a guarantee that a listed bike has a low-step frame.

MANUFACTURER RANGE COMPARISON

Start with the published ranges

Height alone cannot confirm reach, saddle adjustment, standover or control. Even a match to both listed ranges needs a test ride.

Compare reach, saddle adjustment, mounting and control in a test ride.

Aventon Abound SR

Height range only · inseam not published

Rider height: 149.9–190.5 cm

Inseam: Not published

Height guidance note: Converted: 59 inches × 2.54.

Height guidance note: Converted: 75 inches × 2.54.

Reviewed 2026-10-10; next review 2026-10-17. Abound SR product specifications

Gazelle Medeo T9 City

Not enough published guidance

Rider height: Not published

Inseam: Not published

Reviewed 2026-10-10; next review 2026-10-17.

Trek FX+ 1 — Medium Dark Star U.S. model5335258

Within both listed ranges

Rider height: 165–175 cm

Inseam: 77–83 cm

Exact configuration: M · manufacturer frame-size number 50 cm

Manufacturer standover: 78 cm. Default inseam minus listed standover: 2 cm. Arithmetic only; this does not establish safe clearance.

Height guidance note: Exact Medium sizing-table centimetre guidance; inseam 77–83 cm and test fit matter. Not whole-family fit.

Height guidance note: Exact Medium sizing-table centimetre guidance; other sizes remain separate.

Reviewed 2026-10-11; next review 2026-10-18. FX+1 exact model Sizing pane: Medium FX+ 1 model 5335258: Medium sizing and geometry

Share your planning inputs

The link contains height, inseam and your selected options. Anyone with the link can read those measurements. Creating a link does not send it; this calculator does not save a profile. Shared measurements use centimetres internally even when displayed in inches.

What does the frame-size result mean?

Gazelle's general guide multiplies body inseam in centimetres by 0.68. For a suspension seatpost, it subtracts 4 cm from the inseam first. At 80 cm, the arithmetic gives 54.4 cm, or 51.68 cm with that adjustment. This is a brand-specific starting point, not a universal formula, a saddle-height setting, an available frame size or confirmation that the published Gazelle record fits.

For the exact Trek FX+ 1 Medium configuration, the manufacturer lists 165–175 cm rider height and 77–83 cm inseam, frame-size number 50 cm and standover 78 cm. We retain that configuration scope. Inseam minus standover is an arithmetic difference only; this tool does not choose a safe-clearance threshold.

What else should I check on a test ride?

Check reach to the grips, comfortable steering, saddle adjustment within the seatpost's markings, and mounting and dismounting with the intended equipment and load. Ask the dealer to compare adjacent sizes when you sit near a chart boundary. A low-step frame may make repeated mounting easier; it does not settle every fit or handling question.

Missing measurements stay “Not published.” Ranges are manufacturer guidance, not our measurements or test results. Rounded inch conversions remain rounded. After a review date passes, the live comparison flags source review due rather than treating the range as current confirmation.

Sources and scope

Checked October 11, 2026: Gazelle sizing guide and suspension-seatpost adjustment; Gazelle frame forms; Trek FX+ 1 model 5335258 sizing and geometry. Other height ranges link to their dated sources on each card. Only the seven published configurations are included.

Frequently asked questions

Can height alone tell me the right e-bike size?

No. Height guidance can narrow a starting point, but inseam, reach, saddle adjustment, mounting and control still matter. Height-only guidance is not a confirmed fit recommendation.

Is the Gazelle formula universal?

No. It is Gazelle's general guide. Inseam in centimetres times 0.68 gives a starting frame-size number; with a suspension seatpost, subtract 4 cm before multiplying. Confirm the exact model, available sizes and fit with a dealer.

Does inseam minus standover prove safe clearance?

No. The subtraction is arithmetic using a body measurement and the maker's geometry figure. It does not set a universal clearance threshold or establish safe mounting on the actual bike.

Why does a bike say guidance is missing or review is due?

Missing means the published record has no usable typed range for that measurement. Review due means its scheduled evidence review date has passed. Neither status is a fit approval; recheck the exact configuration with the manufacturer.

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