Braking Weight Transfer Calculator (Axle Loads When Braking, Stoppie and Wheelie Limits)
Load on the front and rear axles under hard braking, from the weight, wheelbase, height of the centre of gravity and how hard you brake — plus the point where the rear wheels would lift.
Results
The dashed line marks the value you entered.
What this tool does
When you brake, the car's inertia acts at the height of its centre of gravity while the tyres push at ground level, and that pair of forces tips load onto the front axle: the transfer is mass × deceleration × height ÷ wheelbase. A car with a 0.55 m centre of gravity and a 2.7 m wheelbase moves about one fifth of its weight forward at 1 g. That is why front brakes do most of the work, why a tall, short-wheelbase vehicle nose-dives more, and why a motorcycle can lift its rear wheel (a stoppie) or its front wheel (a wheelie) once the transfer equals the static load on the other axle. Ignores suspension movement and aerodynamic downforce.
Formula
front load = m × (front share + a × h ÷ L) · rear load = m × (rear share − a × h ÷ L) · wheelie limit = front share × L ÷ h
Variables
| Symbol | Meaning | Unit |
|---|---|---|
m | Mass | kg |
wb | Wheelbase | m |
fw | Share of the static weight on the front axle | % |
hc | Height of the centre of gravity | m |
a | Braking deceleration (in g, 1 g = 9.81 m/s²) | g |
FF | Load on the front axle while braking | kg |
FR | Load on the rear axle while braking | kg |
WT | Weight transferred to the front | kg |
FS | Share of the load on the front axle | % |
ML | Hardest braking before the rear wheels lift (g) | g |
MW | Hardest acceleration before the front wheels lift (g) | g |
Worked example
- Mass1500 kg
- Wheelbase2.7 m
- Share of the static weight on the front axle58 %
- Height of the centre of gravity0.55 m
- Braking deceleration (in g, 1 g = 9.81 m/s²)0.8 g
- Load on the front axle while braking1114 kg
- Load on the rear axle while braking386 kg
- Weight transferred to the front244 kg
- Share of the load on the front axle74.3 %
- Hardest braking before the rear wheels lift (g)2.06 g
- Hardest acceleration before the front wheels lift (g)2.85 g
Limitations
- The formula assumes ideal conditions: no friction losses, no air resistance and no efficiency losses unless you enter them.
- The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.