Automotive Brake Calculator


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Brake Calculator
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• A negative percentage indicates a decrease in stroke.
• A positive percentage indicates an increase in stroke.

- A shorter stroke requires a higher pedal effort to generate the same hydraulic pressure.
- A longer stroke will reduce the effort required to generate the same hydraulic pressure.

The numbers already entered are just examples and can be overwritten. If you enter decimals, please use a decimal point. Metric System users: I'm sorry, but you too will have to use the decimal point, as the "comma" will not work.

MC Ø front OLD  = inch
MC Ø rear OLD  = inch
MC Ø front NEW  = inch
MC Ø rear NEW  = inch

Stroke of brake pedal will change by  %


MC Ø front OLD  = mm
MC Ø rear OLD  = mm
MC Ø front NEW  = mm
MC Ø rear NEW  = mm

Stroke of brake pedal will change by  %

To predict pedal stroke before you install different master brake cylinders:
» measure current stroke » compute predicted change » add calculated percentage to current stroke

This calculator calculates the change in brake fluid displacement after changing the Master Brake Cylinder(s).

Not all pedal travel is related to brake fluid displacement and therefore will not change with different master cylinders. Here are some examples:
- Travel to pick up slack between the pedal, pivot point, push rod and master cylinder, etc.
- Travel to make up for flex in the pedal assembly and fire wall.

Here are some actions that require pedal travel AND brake fluid displacement:
- Closing the gap between pads and rotors.
   [a bigger than normal gap while driving, can be caused by worn wheel bearings or warped rotors]
- Expansion of brake lines.
   [minimize the number of curves and replace rubber lines with SS braided lines to limit this]
- Flex in calipers.
   [monoblock calipers usually are stiffer than halves bolted together]
- Aligning sliding calipers on worn bushings or with tapered pads.
   [you can replace rubber bushings with brass ones to reduce these problems]


• For this Pedal Travel Calculator (that only calculates the difference in stroke between the "old" and "new" situation), it does not matter whether you are dealing with a tandem M/C or a dual M/C set-up.

• If you are working on a vehicle with one single M/C operating all four brakes (most cars of the 60's and older), than fill out either the "front" fields or the "rear" fields (leaving the other two empty).


Last Update: 01/01/2017
© Vanrossen 2011-2017