Hydraulic Pressure Front and Rear. This is the amount of hydraulic pressure in the brake lines that is required to decelerate as hard as your tires* and other vehicle properties allow. These other vehicle properties are aerodynamics (positive or negative downforce) and of course the ability of the suspension to keep the tires planted.

*On clean and dry concrete or asphalt, under "full weight transfer", and all wheels beginning to lock up.

1 psi = 6894.8 N/m² = 6894.8 Pa = 6.8948 N/mm² = 0.0007 kg/mm²

Note: I added Hydraulic Line Pressure to the results list because many of you are talking about it in your blogs. Although line pressure plays an important role behind the scenes of this calculator, for selection of brake system components it has no direct value.

Often I see front line pressure vs. rear line pressure being used as an indicator of Brake Bias. However, the only thing it indicates is the line pressure bias, which will be different from Brake (Torque) Bias... unless your front and rear rotor diameters, brake pad friction coefficients and total caliper piston areas are the same too... A condition that is only desirable if dynamic weight distribution under full braking = 50/50 (think race car with engine behind the driver and lots of wing over the rear axle).