ProAV Math: AV Calculators

ProAV Math is a calculator suite built for commercial A/V integrators, sound engineers, and installers, and unlike every other AV calculator, it shows you the work. Every result expands to reveal the formula, the formula with YOUR numbers substituted in, and a numbered step-by-step breakdown with every intermediate value. Check your math, learn the why, or paste the derivation into a design document.

No more black-box answers. See exactly how the number was reached.

**Acoustics**

• SPL at distance (inverse-square level drop)

• dB per doubling of distance (point vs line source)

• dB addition (combine sources, proper power sum)

• Sabine RT60 (predict reverberation time)

• Speaker spacing & ceiling coverage

• Speed of sound from temperature AND humidity

**Audio**

• Delay time (distance to ms, temperature + humidity compensated)

• Series / parallel speaker impedance

• 70V / 100V constant-voltage line loading

• Amplifier power to SPL + headroom vs target

• Level conversion: dBu, dBV and dBm

**Electrical**

• Ohm's law wheel: enter any two of V, I, R, P

• Voltage drop over a wire run (NEC copper resistance, 1Φ & 3Φ)

• Conduit fill: THHN in EMT vs NEC fill limits

**Networking**

• PoE budget: total device draw vs switch budget, with headroom

**Why integrators use it**

• Show-the-work derivation on every calculator, so you can verify or document your design

• Formulas cited to their source (NEC chapter/table, acoustics references)

• Fast, offline, no account, no sign-up

• Clean dark interface built for the field

**Free with ads. One-time Pro unlock removes ads** and supports development. No subscriptions.

**Field-estimate disclaimer:** Results are engineering estimates to speed up planning. Always verify electrical and code-related calculations against the current NEC edition and your local authority having jurisdiction (AHJ) before installation.

**Privacy:** ProAV Math works entirely offline and needs no account. The free version shows ads served by Google AdMob, which may use an advertising identifier; the Pro unlock removes ads.