Radioactive Decay Constant Calculator
⚛ Modern physics. Use the Radioactive decay constant formula to find decay constant λ, half-life: pick the value you want, type the others, and the answer updates as you go.
Decay constant λ1.155 × 10⁻⁴ 1/s
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Decay constant λ | 1/s |
| Half-life | s |
Worked example
Find the decay constant λ when Half-life = 6000 s.
Using λ = ln 2T1/2: Decay constant λ = 1.155 × 10⁻⁴ 1/s.
Frequently asked questions
What is the formula for Radioactive decay constant?
λ = ln 2T1/2.
What do the letters stand for, and what units are used?
Decay constant λ in 1/s, Half-life in s.
How do you calculate decay constant λ?
Put the values into λ = ln 2T1/2. For example, with Half-life = 6000 s, decay constant λ = 1.155 × 10⁻⁴ 1/s.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (decay constant λ, half-life) and fill in the others: it rearranges the formula for you.
