Old Calculators

You can access the old calculators from the menu on the right. There are separate calculators for predicting velocity from power, and power from velocity. There are two version of each for metric and U.S. units. These use the same computations and parameters as the new calculator on the home page. However, the old versions are dual calculators you may prefer when making comparisons.

There are also a pair of calculators for summing up multiple segments of a ride. For example, you can enter a flat segment out to a mountain, up the mountain, and the return trip - a total of four segments - and get an overall time. This is actually an interesting case - does it make sense to take it easy on the flat so you can hammer on the ascent? It's a non-linear problem due to wind resistance.

Finally, there is a calculator where you can enter numeric values for all parameters. For example, you can enter a tire's rolling resistance directly. (If only you knew what it was, on a real road surface.)

Old Calculators:

SPEED from Power, Metric units
SPEED from Power, US units

SPEED from Power, all numeric,

POWER from Speed, Metric units
POWER from Speed, US units

Six segments, Power-Metric
Six segments, Power-US