# Momentum Theory Calculator

 Air Density $$slug / ft^3$$ Rotor Radius $$ft$$ Thrust $$lb$$ Induced Velocity 36.70 $$ft/s$$ Power 433.8 $$HP$$

## Description

This calculator estimates the induced velocity and power consumption of an ideal, hovering helicopter rotor.

## Equations

The following equations are used to estimate the induced velocity $$v_i$$ and power consumption $$P$$ from the input air density $$\rho$$, rotor radius $$R$$, and thrust $$T$$.

$A = \pi R^2$ $v_i = \sqrt{T / 2\rho A}$ $P = T v_i$

For more details including the derivation of these equations see our article on momentum theory.

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