Legacy Documentation: Version 2018.1 (Go to current version)
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# Mathf.InverseLerp

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public static method InverseLerp(a: float, b: float, value: float): float;
public static float InverseLerp(float a, float b, float value);

## Parameters

 a Start value. b End value. value Value between start and end.

## Returns

float Percentage of value between start and end.

## Description

Calculates the linear parameter t that produces the interpolant `value` within the range [a, b].

The a and b values define the start and end of the line. Value is a location between a and b. Subtract a from both a and b and value to make a', b' and value'. This makes a' to be zero and b' and value' to be reduced. Finally divide value' by b'. This gives the InverseLerp amount.

```var walkSpeed = 5.0;
var runSpeed = 10.0;
var speed = 8.0;function Start() {
// parameter is now 3 / 5
var parameter : float = Mathf.InverseLerp(walkSpeed, runSpeed, speed);
}
```
```using UnityEngine;
using System.Collections;public class ExampleClass : MonoBehaviour
{
public float walkSpeed = 5.0f;
public float runSpeed = 10.0f;
public float speed = 8.0f;    void Start()
{
float parameter = Mathf.InverseLerp(walkSpeed, runSpeed, speed);
Debug.Log("InverseLerp: 5, 10, 8 = " + parameter);
}
}
```