How to convert rpm ↔ rad / s unit

* This article is a translation.


If you are a student or a worker involved in engineering or mathematics, you have seen a lot about this unit. rpm (revolution per minute) and rad / s. In this post, I will briefly explain how to convert these two units to each other. I hope it helps.



<Contents>

1. Concept of rpm

2. The concept of rad / s

3. rpm ↔ rad / s
How to convert units




1. Concept of rpm

First of all, let me first introduce the concept of rpm. The rpm is only the first letter of the revolution per minute. If you translate it literally, it will be 'revolutions per minute'.


For example, if an axis is rotating at 1,000 rpm, this axis is doing 1,000 revolutions per minute.



2. The concept of rad / s

rad is the unit after the first three letters of radian. This is the unit of angle. So rad / s represents the magnitude of the change in angle per second. In other words, it is a representation of whether it is rotating at a rotational speed (angular velocity) of several radian per second.


For example, if you say that a ball is spinning at 20 rad / s for a circular motion, it means that the angular velocity of the ball is circular, with an angle change of 20 radians per second.




3. How to convert rpm ↔ rad / s unit

rpm ↔ rad / s unit conversion


Let's start from the left. The process of converting rpm to rad / s. At this time, I understand that rev is written in full name so that it is easy to understand, and the way of converting from rad / s to rpm can be solved by moving from right to left.


If you look at the above formula,
① 1 min = 60 sec: 60 seconds for 1 minute
② 1 revolution = 2π rad: The angle of one rotation is equal to 2π radian.
And is used for unit conversion.