Half-life
Fill in any fields — the empty ones are calculated, so it works in every direction.
Formula
N = N₀·(1/2)^(t/T)
Worked example
Given: Initial amount = 100; Elapsed time = 10,000 yr; Half-life = 5,730 yr
Result: Remaining amount = 29.83
How it is calculated
1. Enter the values you know. 2. The calculator converts them to base units and applies the formula. 3. The result is shown in the unit you choose.
Frequently asked questions
How do I calculate it?
Formula: N = N₀·(1/2)^(t/T). Given: Initial amount = 100; Elapsed time = 10,000 yr; Half-life = 5,730 yr. Result: Remaining amount = 29.83.
Is the calculator free and private?
Yes. It is free, needs no sign-up and runs in your browser — the numbers you type stay on your device.