# How to use e (Euler's number) in Excel

Excel has no constant e, so use EXP: `=EXP(1)` is e and `=EXP(x)` is e to the power x, as in `=$E$1*EXP($E$2*A2)`.

**Excel:** `=$E$1*EXP($E$2*A2)` (Every current version)

**Google Sheets:** the same formula works.

## Example

Sample data (row 1 is the header):

| A | B | C | D | E |
| --- | --- | --- | --- | --- |
| Hours | Bacteria |  | Starting count | 500 |
| 0 |  |  | Growth rate per hour | 0.35 |
| 2 |  |  |  |  |
| 4 |  |  |  |  |
| 6 |  |  |  |  |
| 8 |  |  |  |  |

Formula in B2, filled to B6: `=$E$1*EXP($E$2*A2)`

Result: 500; 1,007; 2,028; 4,083; 8,222

## How it works

EXP raises e (about 2.71828) to the power you give it, so `EXP($E$2*A2)` is e^(0.35 × hours). Multiplying by the starting count in E1 gives the continuous growth model N = N₀e^(rt). The `$` signs keep the start and rate fixed as the hours change.

## Other ways

- `=$E$1*EXP(1)^($E$2*A2)`: Raises e itself to the power. Longer, but it shows that EXP(1) is e.

## Common mistakes

- Typing `=e^2` returns #NAME? because Excel reads e as a name. Use `=EXP(2)`.
- Typing 2.718 for e is an approximation; over many periods the error grows. EXP uses the full-precision value.

## Questions

**How do I undo EXP?**

LN is its inverse: `=LN(EXP(5))` returns 5.

**How do I calculate continuous compound interest?**

Use `=P*EXP(r*t)` with the rate as a decimal, like 0.05 for 5%.

Every formula and result on this page was checked by running it in the Spreadsheet Practice formula engine on 2026-10-30.

Source: https://spreadsheetpractice.com/formulas/use-e-in-excel