Free AV design calculators
The six calculations every AV designer, consultant and buyer makes: screen size, projector brightness, throw distance, LED wall resolution, ceiling speakers and amplifier power. Get an instant answer, then a proposal.
Your result
Get a proposal based on thisStarting-point estimate based on standard industry rules. A UBM specialist will confirm it for your room.
How this is calculated
Uses the widely used 4-6-8 rule: the farthest viewer should sit no more than 8 times the image height away for video, 6 times for presentations and 4 times for detailed content. Image height = farthest distance ÷ factor; the diagonal follows from the aspect ratio.
Your result
Get a proposal based on thisStarting-point estimate based on standard industry rules. A UBM specialist will confirm it for your room.
How this is calculated
Lumens = target screen brightness (nits) × screen area (m²) × π ÷ screen gain. Target brightness rises with ambient light. We add 30% headroom so the image stays bright as the light source ages or in eco mode.
Your result
Get a proposal based on thisStarting-point estimate based on standard industry rules. A UBM specialist will confirm it for your room.
How this is calculated
Throw distance = throw ratio × image width. The throw ratio is listed in every projector's specifications; zoom lenses give a range. Ultra short throw projectors (below 0.4) sit just above or below the screen.
Your result
Get a proposal based on thisStarting-point estimate based on standard industry rules. A UBM specialist will confirm it for your room.
How this is calculated
Resolution = wall size ÷ pixel pitch. A common rule of thumb is a minimum viewing distance in metres roughly equal to the pitch in millimetres, with comfortable viewing at about 2.5 to 3.5 times that.
Your result
Get a proposal based on thisStarting-point estimate based on standard industry rules. A UBM specialist will confirm it for your room.
How this is calculated
Coverage diameter at ear height = 2 × (ceiling height − ear height) × tan(dispersion ÷ 2). Spacing is that diameter for edge-to-edge, 0.707 × for minimum overlap and 0.5 × for full overlap. Speakers = ceil(length ÷ spacing) × ceil(width ÷ spacing).
Your result
Get a proposal based on thisStarting-point estimate based on standard industry rules. A UBM specialist will confirm it for your room.
How this is calculated
Total load = number of speakers × tap wattage. Add 25% headroom so the amplifier never runs flat out, then choose the next standard 70V/100V amplifier size, or split into zones for large systems.
AV calculation FAQs
How do I calculate the right screen size for a room?
Measure the distance to the farthest viewer. For presentations, divide it by 6 to get the minimum image height; for video use 8 and for detailed content use 4. Then convert the height to a diagonal using the aspect ratio.
How many lumens does a classroom projector need?
It depends on screen size and room light. A 100 to 120-inch screen in a classroom with lights on typically needs several thousand lumens; use the projector brightness calculator above for your exact room.
How far should a projector be from the screen?
Multiply the image width by the projector's throw ratio. For example, a 2.2 m wide image with a 1.5 throw ratio needs the projector about 3.3 m from the screen.
What pixel pitch do I need for an LED video wall?
As a rule of thumb, the minimum viewing distance in metres roughly equals the pixel pitch in millimetres; for comfortable viewing, multiply by 2.5 to 3.5.
How many ceiling speakers do I need for my office?
Work out the coverage circle of each speaker at ear height, choose spacing for the quality you need, and divide the room length and width by that spacing. The ceiling speaker calculator does this for you.
Are these calculators accurate enough to buy equipment?
They give reliable starting points based on standard industry rules. Final designs should account for room acoustics, content, ambient light and product specifications, which UBM checks in a free consultation.
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