How to make your game run the same with low or high FPS.

Hi, Im having an issue. When the game was vsynced at 50fps there was no issue, but when the fps gets higher its a clear issue. I used the method of multiplying a value by a number between 0 and 1 to decline the value a percentage each update. Say the value is 100 and I multiply it by .95 each frame. It gets smaller and smaller at a reasonable rate. However, when vsync is off as you can imagine the issues that causes. And this isnt the sort of thing you can multiply by Time.deltaTime to fix, so I was wondering if anyone had mathematics that could help me right now.

Say I have this in the game limited at 50 frames but wish to start using it on a non vsynced game, can anyone help me perfect the equation?:

float value = 362.4f;
float rate = .95f;
void Update() {
    float *= rate;
}

Use the Continuously Compounded Interest in this situation.

float value = 362.4f;
float rate = .95f;
void Update() {
    float *= rate;
}

can be redone as

float e = 2.71828f;//Do not change. This is a constant.
float value = 362.4f;
float rate = -.05f;
void Update() {
    value *= Mathf.Pow(e, rate*Time.deltaTime*50);//Multiplied by 50 because its rather slow
}