Enter the specific heat of the air or fluid being analyzed and the acceleration due to gravity to calculate the lapse rate.

## Lapse Rate Formula

The following formula is used to calculate a lapse rate.

L = g / Cp

- Where L is the lapse rate (C/km)
- g is the acceleration due to gravity (9.81m/s^2)
- Cp is he specific heat of the gas at constant pressure

## Lapse Rate Definition

A lapse rate is defined as the rate at which an atmospheric variable such as temperature changes with a change in altitude.

## Why does lapse rate occur?

A lapse rate occurs because as a change in altitude occurs, a change in air density occurs. The less dense air causes changes to pressure and temperature. The change in pressure is caused by the effect of gravity acting on the air.

## Lapse Rate Example

How to calculate lapse rate?

**First, determine the acceleration due to gravity.**On earth this is equal to 9.81 m/s^2.

**Next, determine the specific heat.**Calculate the specific heat of the gas.

**Finally, calculate the lapse rate.**Calculate the lapse rate using the equation above.

## FAQ

**What is lapse rate?**

A lapse rate is a measure of the change in temperature with respect to altitude of a gas.