Measure rotor leverage, braking torque, and axle force with practical inputs. Review each balance result. Build safer brake setups through clear measured comparisons today.
Use one consistent clamp-force definition per rotor. Values describe theoretical capacity, not a substitute for brake testing.
D is rotor diameter in metres. k is the effective-radius factor. Clamp force is the total normal force applied to one rotor. The calculator first finds torque per brake, then multiplies it by the brake count for each axle. Finally, it divides axle torque by loaded tire radius to estimate available road force.
Use matching units shown in the labels. Change one component at a time when comparing setup options. Do not treat a calculated percentage as a final brake-bias setting. Confirm the system through engineering review, controlled testing, and legal requirements.
| Input | Front | Rear | Purpose |
|---|---|---|---|
| Rotor diameter | 340 mm | 310 mm | Sets friction leverage. |
| Clamp force per rotor | 16,000 N | 12,000 N | Sets pad normal force. |
| Pad friction coefficient | 0.42 | 0.42 | Estimates friction force. |
| Tire rolling radius | 320 mm | 320 mm | Converts torque into road force. |
Brake force distribution describes how total stopping effort is shared between front and rear axles. Rotor size changes leverage. A larger disc places pad friction farther from the wheel center. That longer lever arm produces more braking torque from the same clamp load. Torque alone does not describe tire force. Tire radius converts axle torque into braking force at the road.
This calculator estimates the available capacity of each axle. It uses rotor diameter, effective pad radius, clamp force, pad friction, brake count, and tire radius. The result is a theoretical mechanical balance. It is not a complete vehicle braking design. Real vehicles also transfer weight forward during deceleration. Suspension geometry, tire grip, pad temperature, hydraulic bias, ABS calibration, and road conditions matter.
Use effective radius rather than rotor outside radius. Pads do not act at the disc edge. The average contact center sits inward from it. The radius factor estimates that location. A value near 0.82 to 0.90 is common for a broad first estimate. Measure the pad sweep when accuracy matters. Multiply outer rotor radius by this factor before calculating torque.
Clamp force means the total normal force squeezing one rotor. It may come from caliper piston area and hydraulic pressure. Confirm whether a quoted value represents one pad, one caliper half, or the complete caliper. Enter one consistent total per wheel. The calculator multiplies by the number of brakes on each axle. Most passenger vehicles use two front and two rear brakes.
Pad friction varies with compound, temperature, pressure, moisture, and speed. A constant coefficient is a useful planning approximation. It does not predict fade or pedal feel. Enter values from manufacturer data where available. Conservative estimates are better than optimistic assumptions. A distribution that looks ideal on paper may still lock a tire early.
The calculated front percentage is capacity bias, not guaranteed operating bias. During a stop, pressure control and wheel slip determine actual force. A front-heavy vehicle commonly needs more front braking under hard deceleration. However, extreme front bias can lengthen stops by underusing rear traction. Excessive rear bias can cause instability. Treat this output as a comparison tool before detailed testing.
Target deceleration creates a required total road force. The calculator compares it with the estimated braking force capacity. A utilization below one hundred percent suggests theoretical capacity exceeds that target. It does not guarantee performance. Tire grip can remain the limiting factor. Use controlled testing, professional review, and applicable regulations before modifying a road vehicle.
Rotor diameter changes thermal behavior too. Larger rotors usually accept more heat and may cool better. Those benefits are outside the torque calculation. Unsprung mass increases. Balance leverage gains against packaging, wheel clearance, and component compatibility. Use matched components. Check caliper brackets, pad sweep, wheel offset, brake hoses, and master cylinder travel. Record every assumption. Repeat calculations after changing any component or wheel size again.
No. Rotor diameter changes leverage, but clamp force, pad friction, brake count, tire radius, and hydraulic behavior also change the result. This calculator includes those values so rotor size is not treated as the only variable.
Usually, yes, when other inputs stay fixed. A larger effective rotor radius produces more torque per unit clamp force. A change in rear clamp force, pad compound, tire radius, or brake count can offset that increase.
It estimates where the pad’s average friction force acts on the disc. Pads work inward from the rotor edge. Multiply the outside radius by this factor to obtain a more realistic torque radius.
It may be derived from hydraulic pressure and piston area, or obtained from engineering data. Use the total normal force acting across one rotor. Confirm whether a source reports one piston, one pad, or total caliper force.
Use a conservative coefficient for your pad compound at the expected temperature. Friction changes with heat, pressure, speed, moisture, and rotor condition. Manufacturer dynamometer data is preferable to a generic value.
Brakes create wheel torque. Tire radius converts that torque into longitudinal force at the road. Different loaded tire radii can alter the front and rear force shares, even with unchanged brake torque.
Yes. Set the axle brake count to one. This is useful for certain motorcycles, trikes, prototypes, or special machinery. Make sure each entered clamp force matches the actual single-rotor arrangement.
Capacity is the maximum theoretical force under the entered assumptions. Actual force depends on pedal input, hydraulic proportioning, tire slip, load transfer, ABS action, and surface grip during the stop.
No. ABS can control wheel slip, but poor base balance can affect heat loading, pedal behavior, intervention frequency, stability, and stopping consistency. Proper mechanical and hydraulic matching remains important.
Use it as an early comparison tool only. Track use needs thermal modeling, pad temperature data, dynamic load-transfer analysis, tire data, hydraulic calculations, and controlled testing by qualified people.
Verify component fit, wheel clearance, master-cylinder compatibility, hose routing, fluid capacity, legal requirements, and professional advice. Then test in a controlled setting. Never rely on a calculator output alone for public-road safety.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.