# Fold Increase Calculator

## Fold Decrease Calculator

Enter the initial value and final value, click the calculate button, and the calculator will display both fold increase and fold decrease. Fold increase means a number is increased by a multiple of the original number, and fold decrease means a number is decreased by a multiple of the original number. For a better understanding, see the formulas and examples below; they will help your understanding more better.

## Fold increase and fold decrease formulas with examples

The formula for calculating fold increase (\(FI\)) is given:

\[ FI = \frac{F}{I} \]This represents how much the final number of cells (\(F\)) increases compared to the initial number of cells (\(I\)).

The formula for calculating fold decrease (\(FD\)) is given:

\[ FD = \frac{I}{F} \]This represents how much the initial number of cells (\(I\)) decreases compared to the final number of cells (\(F\)).

Where:

- \(FI\): Fold Increase
- \(FD\): Fold Decrease
- \(I\): Initial Number of Cells
- \(F\): Final Number of Cells

Let's say the initial number of red blood cells (\(I\)) is \(4,000,000\) and after a period of production, the final number (\(F\)) increases to \(20,000,000\).

Using the fold increase formula:

\[ FI = \frac{20,000,000}{4,000,000} = 5 \]Therefore, the final number of red blood cells is five times greater than the initial number.

Now, consider the initial number of white blood cells (\(I\)) as \(10,000\) and after an immune response, the final number (\(F\)) decreases to \(2,000\).

Using the fold decrease formula:

\[ FD = \frac{10,000}{2,000} = 5 \]Therefore, the initial number of white blood cells is reduced to one-fifth of the final number after the immune response.

## What is fold increase and decrease?

The terms “fold increase” or “fold decrease” are commonly used in scientific, mathematical, and biological contexts to express the ratio of one quantity to another It indicates how much one value has changed relative to another.

For example, if you have an initial value of 5 and it increases to 20, the fold increase would be 20 divided by 5, which is 4. So, in this case, there is a 4-fold increase.

Conversely, if the initial value of 20 decreases to 5, the fold decrease would also be 20 divided by 5, which is 4. So, in this case, there is a 4-fold decrease.