How much power do I need for a venue?

For small venues (50 people): 200-500W. Medium venues (200 people): 500-2000W. Large venues (500+): 2000-10000W+. These are rough guidelines — the actual requirement depends on speaker sensitivity, distance, room acoustics and desired SPL.

Why do I need more power than the calculation shows?

The calculation gives the minimum continuous power. Music has peaks 6-20 dB above average level. You need headroom (typically 6-10 dB) to handle these peaks cleanly. Under-powered amplifiers clip, producing harsh distortion that can damage tweeters.

What is speaker sensitivity?

Sensitivity (dB SPL at 1W/1m) tells you how loud a speaker is per watt of power. Typical PA speakers are 95-100 dB. High-efficiency horn-loaded speakers can reach 105-110 dB. Every 3 dB more sensitivity halves the required amplifier power.

Should I match amplifier power to speaker power rating?

A common recommendation is to use an amplifier rated at 1.5-2 times the speaker continuous power rating. This provides headroom for peaks. Under-powering is more dangerous than over-powering because clipping produces damaging harmonics.

AudioCalcs

Speaker Power Calculator — Required Amplifier Wattage

Calculate required amplifier power for a target SPL at a given distance.

Target SPL

Distance

Speaker Sensitivity

Headroom

How We Calculate This

Required SPL at 1 metre

SPL at 1m = Target SPL + 20 × log10(distance)

Required Power

Power (W) = 10^((SPL at 1m − Sensitivity) / 10)

With Headroom

Amp Power = Required Power × 10^(Headroom dB / 10)

Frequently Asked Questions

Related Calculators

Speaker Impedance Calculator

Calculate total load impedance for series, parallel and series-parallel speaker wiring configurations. Free online audio calculator.

SPL Calculator

Calculate sound pressure level at any distance from speaker sensitivity and amplifier power. Essential tool for PA and event planning.

Crossover Calculator

Calculate capacitor and inductor values for passive speaker crossover networks at various filter orders. Free online audio calculator.

Amplifier Calculator

Calculate required amplifier power, headroom margin and speaker matching for PA systems and studio monitors. Free online calculator.

Speaker Wire Calculator

Calculate the speaker wire gauge (AWG) needed for your cable length, speaker impedance and acceptable power loss. Free calculator.

Last updated: February 2026

All calculations are estimates based on standard formulas. Always verify results for critical applications.