DbPower · engineering calculator

DbPower db power ratio

Express a power change as dB for audio or RF screening notes

TECHNICAL UTILITY · DB_POWER_RATIO

Result

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dB = 10 · log10(power1_w / power2_w)

How to use this estimate

Compute power ratio in decibels from two power levels. How it works: dB = 10 · log10(power1_w / power2_w). Out of scope: SPL / dB SPL; voltage dB (20·log10); A-weighting; FFT analyzers. Informational calculation for the stated inputs only. Does not certify code compliance; confirm manufacturer data where it applies.

Sources, methodology, and assumptions

Methodology

dB = 10 · log10(power1_w / power2_w)

Assumptions

Same impedance basis for both powers; Positive powers. Informational calculation for the stated inputs only.

Out of scope

SPL / dB SPL; voltage dB (20·log10); A-weighting; FFT analyzers

Sources

NIST SP 811 — unit consistency context (not exact formula page) — NIST
NIST logarithmic / ratio unit context — NIST

Last technically reviewed: 2026-09-11