To find the number needed to treat, take 1 and divide it by the absolute risk reduction.
Formula:
Contents
NNT = 1 ÷ ARR
Table of Variables
| Variable | Meaning |
|---|---|
| NNT | Number Needed to Treat |
| ARR | Absolute Risk Reduction |
What is a Number Needed to Treat Calculator | NNT Calculator 2025
Let’s say there’s a new drug on the market. It claims to reduce the risk of heart attacks. Sounds great — but how many people actually need to take it for one person to benefit? That’s what the Number Needed to Treat Calculator tells you.
The number might be 2, 5, or 100 — and each one means something. If the NNT is 4, that means treating four people will help one. It’s a simple number, but it says a lot. This tool makes it easy to find that number using the number needed to treat formula, which is just 1 divided by the absolute risk reduction.
If you’ve ever seen a number needed to treat example and thought, “How do I actually calculate this?” — you’re in the right place. This is the go-to calculator for students prepping for USMLE, researchers analyzing NNT for common drugs, or anyone wanting to know what is a good number needed to treat. It's not just a formula — it's a shortcut to clear, clinical insight.
