About the Decibel Calculator
Decibel Calculator does the math for you. Enter your values in the format shown and the result appears immediately — no spreadsheets, no formulas to remember, and nothing is uploaded to a server.
How Decibel Calculator works
Power level in dB = 10 × log₁₀(ratio).
Worked example: A power ratio of 100 = 10 × log₁₀(100) = 20 dB
Common uses
- Quick everyday math.
- Double-checking figures fast.
- Schoolwork and homework.
- Finance, health and planning.
Frequently asked questions
Is my data uploaded?
No — the calculation runs entirely in your browser, so your data stays private.
Is it free?
Yes — completely free with no sign-up.