Half-Life Calculator
Calculate radioactive decay using the half-life formula. Enter initial amount, half-life period, and elapsed time to find remaining substance.
How to Use the Half-Life Calculator
- Enter the known physical values in the corresponding fields.
- Select the appropriate units if multiple options are available.
- The unknown value is computed instantly from the formula.
- Review the result and the formula explanation below.
Quick Reference
| From | To |
|---|---|
| Speed of light | 299,792,458 m/s |
| Gravity (g) | 9.807 m/s² |
| Avogadro's number | 6.022 × 10²³ |
| Boltzmann const. | 1.38 × 10⁻²³ J/K |
| Elementary charge | 1.602 × 10⁻¹⁹ C |
| Planck's const. | 6.626 × 10⁻³⁴ J·s |
Use Cases
- •Solving physics homework or exam problems with the correct formula.
- •Verifying experimental measurements and calculations in the lab.
- •Understanding physical relationships between quantities.
- •Quick engineering calculations for design or estimation.
Formula
N = N₀ × 0.5^(t / t½). Decayed = N₀ - N. Decay % = (Decayed / N₀) × 100.
Frequently Asked Questions
How to use?
Enter the data and click the calculate button.
What is half-life?
Half-life is the time required for half of a radioactive substance to decay. After one half-life, 50% remains; after two, 25%; and so on.
Calculation accuracy?
Calculations are performed with high precision.
Is it free?
Yes, all calculators are completely free.