Lighting calculator
DMX Universe & Address Calculator
A DMX512 universe carries 512 channels, so a fixture with a 16-channel footprint fits 32 times per universe. Enter your fixture footprint and count to get the universes required and the start-address list, and use the DIP switch section for legacy fixtures addressed in binary.
The fixture mode footprint, e.g. a mover in 16-channel mode.
For legacy fixtures addressed with a 9-switch DIP bank.
Formulas
Fixtures per universe
floor(512 / footprint)- footprint:
- channels the fixture mode occupies
Universes needed
last universe reached while packing whole fixtures from the first address- first address:
- reduces the usable space in universe 1 when it is greater than 1
DIP switch address
address = Σ (switch value × state), switches valued 1,2,4,...,256How it works
DMX addressing is bookkeeping: each fixture listens starting at its address for as many channels as its mode occupies, and two fixtures overlap the moment their ranges intersect. Packing whole fixtures per universe (this tool never splits a fixture across the universe boundary) is standard practice, because a footprint straddling channel 512 cannot work.
Universe counts drive infrastructure. Console output capacity, nodes, and sACN/Art-Net network planning all start from this number, and the answer changes with fixture mode: the same mover might occupy 16 channels in basic mode and 39 in extended. Compute with the mode you will actually run.
The DIP switch bank on legacy fixtures sets the address in binary: switch 1 adds 1, switch 2 adds 2, up to switch 9 adding 256. Address 1 is just switch 1 up. Some fixtures label the first switch as the "+1" only when a tenth switch selects a mode; when a fixture is off by one, it is usually using the "address = DIP value + 1" convention, so set one less.
Worked example: 24 movers in 16-channel mode starting at address 1
- 1.Fixtures per universe: floor(512 / 16) = 32, so 24 fit in one universe.
- 2.Universes: ceil(24 / 32) = 1. Addresses run 1, 17, 33, ... 369.
- 3.For DIP address 257: 257 = 256 + 1, so switches 9 and 1 up, all others down.
One universe, addresses every 16 channels, and DIP 257 = switches 1 and 9.
Fixtures per universe by footprint
| Footprint | Fixtures per universe | Channels used |
|---|---|---|
| 1 ch (dimmer) | 512 | 512 |
| 8 ch | 64 | 512 |
| 16 ch | 32 | 512 |
| 24 ch | 21 | 504 |
| 39 ch (extended mover) | 13 | 507 |
| 52 ch | 9 | 468 |
Field notes
- Leave address gaps between fixture groups on busy universes; retrofitting a fixture into a packed universe mid-tour is misery.
- Label universes at the opto-splitter, not just in the console; the tech swapping a cable at 2 AM reads tape, not patch screens.
Frequently asked questions
How many DMX universes do I need?
Starting at address 1, divide 512 by the channel footprint, round down for fixtures per universe, then divide your fixture count by that and round up. A later first address leaves fewer usable channels in universe 1, which this calculator accounts for while packing. Mixed rigs need a full patch calculation.
Can a fixture address span two universes?
No. A fixture reads consecutive channels within one universe, so the last valid start address is 512 minus footprint plus 1. Plan packing so nothing straddles the boundary.
Why is my DIP-switched fixture off by one?
Two conventions exist: address equals the binary value of the switches, or address equals the value plus one. If channel 1 responds when you set 2, your fixture uses the plus-one convention.