The method
Four stages, two photographs each
Photograph yourself twice to build a digital body, photograph each riding position on the bike, then get every position ranked by aerodynamic drag and the gaps between them in watts.
No position is treated as the reference. Every position you send is compared against every other one, so the ranking comes out of your own set rather than out of a baseline nominated in advance.
01 — Digital body
Create your personal digital body from only two pictures
Aerodynamic drag depends on your shape and how much of it faces the wind. Before any position can be compared, WattCut needs a model of your body — and two photographs plus your height are enough to build one.
Read stage 0102 — Positions
Photograph the positions you want to compare
WattCut compares positions against each other. None of them is a reference: you are not measuring improvements from a baseline you nominated, you are finding out how the positions you actually ride rank against one another.
Read stage 0203 — More positions
Add as many as you are curious about
Two positions answer one question. Four or five answer the question you actually have: of the positions available to you, which is worth riding? Each one is photographed the same way and enters the same comparison.
- No baseline, no privileged position
- One change at a time
- The fastest position is not automatically the best
04 — Report
We run the simulation and send you a report
Once a submission is in, every position in it is compared against every other, and the result comes back as a report. The central figures are always differences between your own positions — never isolated numbers.
Read stage 04
Still deciding whether it applies to you?
The questions and answers cover accuracy, what a comparison can and cannot tell you, and how this differs from a bike fit. The technology page covers what the solver is actually doing.
Get aero. Go faster. Same watts.
Free to join · 2 for €35 · 5 for €80 · Closes 31 October 2026