Five calculators for a load-in. On a phone, in the dark, with no signal.
Five things a stage electrician works out on site, and nothing else. No account, no sign-in, and it never goes online — including the Network screen, which plans a network without ever touching one. Type numbers in, read numbers back.
The same five calculators also run in a browser, so you can follow along without the app in your hand — the web version is the same formulas, the same refusals and the same rounding, and every screen below links straight to it.
The only thing it remembers between launches is whether you want light or dark. Nothing about a rig is stored.
Every screen is laid out the same way, and three things tell you what you are looking at. Learn these once and the rest is obvious.
Results sit above the controls on every screen, so the things you touch stay within reach of a thumb. To put the keyboard away, tap anywhere outside the field, or use Done above the keys.
The meter shows the draw against the circuit. The orange line on the bar is the 80% limit, and the scale names it — 0 16 A 20 A on a 20 A breaker. A load running three hours or more counts as continuous and code limits it to 80% of the breaker, which is nearly every stage fixture, so that line is the one that matters, not the breaker rating. The rule itself is printed beside the figure it produced: Usable · 80%.
Up to that line the bar is simply filled. Only the part over it turns orange, so the bar tells you how far over you are rather than only that you are. The readout above turns orange too, and the app says how many circuits to split across. When it can prove that split is the fewest possible, it says so; when it can only prove the split works, it says that instead.
A fixture that draws more than a whole circuit is called out separately rather than squeezed in.
Switch Supply to three phase and set the feeder rating, and the rig is dealt across L1, L2 and L3 — heaviest first onto whichever phase is lightest so far. That is what a person does at a rack, and with equal circuits it comes out as 1, 2, 3, 1, 2, 3. It is a split that balances well, not a proof that nothing balances better, and the app does not claim otherwise. All three are drawn against one scale, so an imbalance is a shape rather than three numbers to subtract in your head.
Deal decides what gets spread across the three, and the two answers suit different moments.
By circuit takes the circuits as they are and puts each one on a phase whole. That is the question when the circuits are already run — a rack wired to a pattern, a road box with its own breakers, anything already in the air. It balances as evenly as those circuits allow and no more.
By fixture deals the individual fixtures across the phases first, then packs each phase its own circuits. That is the question while the rig is still on paper and which fixture lands on which circuit is yours to choose.
The difference is worth knowing and it is not free. Six 5 A fixtures on a 20 A breaker pack into two circuits of 15 A, and two circuits across three phases leaves one sitting empty — 15, 15 and nothing, a spread of the whole rig. Dealt as fixtures instead they go two to a phase: 10 A each, dead level, nothing in the neutral. That costs a third circuit. When it costs one the app says so under the spread, because a circuit you have not got is a real answer to give.
The breaker still applies. The feeder is what comes into the rack; the breaker is on each circuit out of it. The rig is split into circuits against the breaker first, and it is those circuits that go onto the phases — change the breaker and the split changes, and so does the balance.
Which is why trying a different breaker sometimes levels the phases up. A circuit cannot be split, so when you deal by circuit the circuits are the floor on how level the three can get. With circuits of equal size they come out level when their number divides by three, and exactly one circuit apart when it does not — so a smaller breaker does not make perfect balance more likely, it makes the leftover smaller when balance is not available.
Spread is how far apart the busiest and the quietest phase are, and it names them, because the fix is to move a circuit from one to the other. It is not the neutral current, although for some rigs the two happen to be the same number.
The feeder follows the same 80% continuous rule a branch circuit does. If one phase goes over it, the app says so and says that moving circuits will not help: balance and capacity are different problems. A perfectly level rig can still be too big for the feeder.
The three phases peak a third of a cycle apart, so when they carry the same current they cancel in the neutral and it carries nothing. Whatever does not cancel comes back down it. That is what this figure is — real current in a real conductor, not an allowance or a reservation — and it is a floor.
Dimmers at anything but full, and the supplies inside LED fixtures, draw current in pulses rather than a clean sine wave. A large part of that is third harmonic — and the third harmonic arrives on all three phases at the same instant instead of a third of a cycle apart. So where the fundamentals cancel in the neutral, the harmonics add. A perfectly balanced all-LED rig still puts current down the neutral, and it can rival what a phase is carrying. It is why feeder neutrals get oversized.
Size a neutral from a measurement or from the rack's own rating, never from this number. The app does not try to calculate the harmonic part: it would need each fixture's current waveform at each dimmer level, which is not published anywhere, and a plausible invented figure is the thing this whole app exists to avoid.
Two panels, because there are two jobs. DIP switches is the fixture in front of you — its switches, the address they set, and what kind of fixture is doing the counting. Patch is the paperwork for a row of them, on its own inputs.
Nine switches, whatever your fixture has. 29 is 512, which is the whole universe, so there is no tenth address bit to set. A fixture with ten, eleven or twelve switches uses the ones past the ninth for functions — response speed, lamp on at power up, what to do when DMX goes away — and its manual lists those under their own heading. Set them from the manual, not from the address.
Check the offset before you trust the pattern. Fixtures disagree about it, and the two readings give different switches for the same address: 137 is switches 1+4+8 under one and 4+8 under the other. Pick whichever your fixture's manual describes:
| Setting | Means |
|---|---|
| All off = 1 | The address is the switch total plus one |
| Switch 1 = 1 | The address is the switch total |
Nine switches counting from the total reach 511 at most, so a fixture set that way cannot be addressed 512 at all. The app says so and greys out the switches rather than offering the nearest pattern.
Enter where the run starts, how many channels one fixture uses and how many are in it, and the addresses are laid out for you. The addition is trivial, which is exactly why it goes wrong — done sixteen times in your head on a ladder it slips once, and every fixture after that answers somebody else's cues.
The run has its own start address, separate from the one driving the switches above. They are different jobs: the switches are for setting one fixture by hand in front of you, and a run is paperwork for a row of them that usually begins somewhere else. Working out a run never disturbs a fixture you are part way through setting.
The step that is not addition: a fixture cannot straddle a universe boundary. There is no channel 513, so one that would land on 500 with sixteen channels does not get 500–515 — it moves whole to address 1 of the next universe, and the tail of the old one is stranded. The list draws that break rather than describing it.
Two figures under the list, and both are things the list itself cannot show. Fits from here counts from the address you gave, not from 1 — starting at 400 you have 113 channels in front of you, not 512 — so it answers "how many can I get in before the break", and zero means the first one will not go where you asked. Next one starts at is the address to carry to the next batch, following the same boundary rule.
This screen plans a network. It does not touch one — nothing here sends or listens, and the app has no way to look at what is actually on the wire.
/8, which is how
the arithmetic works rather than how the gear is set. The readout above prints both,
and draws the mask as what it actually is: a cut through the 32 bits of the address,
with everything left of the line the network and everything right of it the host.Change the address or the mask and the scheme stays selected, on purpose. If it quietly switched itself to Custom you would lose the warning at the exact moment it starts being true: a node left on its factory 255.0.0.0 and a console set to 255.255.255.0 disagree about where the network ends, and everything works until the first packet has to cross that boundary.
sACN has no range to be wrong about — E1.31 runs over any IP network and specifies only the multicast group a universe is sent to. So the app offers no sACN scheme rather than inventing a plausible one.
Type any device's address and the app says whether it shares this network — and shows the working rather than only the verdict: under a 255.0.0.0 mask that address is on 192.0.0.0, not 2.0.0.0. This is the fault that eats the first twenty minutes of a load-in, and it looks like a cable problem the whole time.
This is the addressing only. Two boxes on one subnet still need a cable, a switch port and a VLAN that agree, and the app cannot see any of those.
List what is going on the network — a console, four nodes, a couple of laptops — and the addresses are handed out in order from the first host address. Ask for more boxes than the subnet holds and the app says how many have nowhere to go and which mask would fit them, rather than only that something is wrong.
What this is for: a console hands you one universe number, and the gear rarely takes it that way. Many Art-Net nodes ask for Net, Sub-Net and Universe as three separate fields in their setup menu, and a managed switch filtering multicast wants the sACN group address. Type the universe here and read off whichever form the box in front of you is asking for.
| Universe 256 | |
|---|---|
| sACN group | 239.255.1.0, UDP 5568 |
| Art-Net | Net 1 · Sub 0 · Uni 0, UDP 6454 |
sACN puts the universe number in the bottom two octets of 239.255.0.0, so universe 256 is 239.255.1.0 — the carry into the third octet is the part that gets dropped on a notepad. Art-Net instead splits a 15-bit Port-Address across three fields, which is the DIP switch problem one layer up.
They are the same number split two different ways — sACN into two octets, Art-Net into 7, 4 and 4 bits — which is why universe 260 reads as 239.255.1.4 for one and Net 1 · Sub 0 · Uni 4 for the other.
The two do not start counting in the same place: sACN's first universe is 1, Art-Net's first Port-Address is 0. Consoles differ on which they show you, so match the number on the console to the number on the node rather than assuming they mean the same thing.
Kelvin does not scale with what the eye sees — 3200K→3400K is obvious, 9000K→9200K is not — which is why gel makers publish a mired shift instead. The scale under the readout marks every gel in stock, so you can see how close the nearest one lands.
A shift under 8 mireds is reported as needing no correction: the eye will not read it. If nothing lands within 25 mireds the app says to stack two, since mired shifts add.
Stock lists all eleven gels with Lee, Gam and Rosco numbers, whether or not you are correcting anything.
Enter the sheet size, the frame size and how many frames you need, and the app says how many come out of one sheet, how many sheets that is, and what goes in the bin. The units are a label and nothing is converted — the yield is a ratio, so it is the same number in inches or centimetres as long as both measurements are in the same one.
Shape sits above the frame row and decides how many numbers it asks for. Square is one measurement — the side — because an S4 frame is 6.25 in both ways and typing that twice tells the app nothing it had not assumed. Rectangle gives you two, for the frames that are not square. Switching between them does not lose anything: the second measurement is held while Square is on and comes back when you turn it off.
It cuts on a grid, because that is what a straight blade against a straightedge can actually do. A cleverer arrangement that yields one more piece and cannot be cut is worse than the honest number.
On a rectangle, both ways round are shown rather than the better one being picked for you. Colour has no grain, but silk and the other directional diffusions do — they scatter along one axis, so a piece turned ninety degrees spreads the beam the other way. On those the orientation is part of the look, not a choice about yield. A square piece turned ninety degrees is the same piece, so on Square there is no second way round to report and the screen does not pretend there is.
Start from picks which of those two questions you are asking. Both read the same formula; it only decides which two numbers are yours to type and which one the screen works out.
The big number is the beam — the usable pool, 50% of maximum and above. The field is the whole beam down to 10%, and runs about half as much again. Plan coverage from the beam, not the field.
The section below draws the cone at true scale, so the shape you see is the lens's actual field angle: a 10° tube is a needle, a 50° is a fan. Both widths are named underneath it, in the same colours the picture uses — a filled square for the beam, a dashed line for the field.
Wider leaves no dark edge but may spill a little past what you asked for. Narrower never spills but may fall a touch short at the very edge. Both are shown because which one you want depends on the job — an isolation special wants narrower, a wash that must not leave a gap wants wider — and that is not a call this screen can make for you. Go and get the degree it names: the answer is a 26°, not a barrel size you would have to translate first. Each option states the diameter it actually puts on the target at your throw, not just how many degrees it is off by: the same two-degree gap can be a foot short or a foot long depending on how far back the fixture is.
The list is angles, not fixtures — a lens tube carries its degree printed on the barrel, so that is the one label you can check against the thing in your hand. The degree is nominal, though: the field angle a fixture actually measures differs from it, so anything critical comes off that fixture's own photometric data.
This is the one setting that can trip a breaker if you ignore it.
For tungsten, watts and amps convert exactly, and entering wattage is fine. For LED and discharge fixtures they do not: power factor means the real current is higher than the wattage suggests — the direction that trips a breaker rather than the one that wastes capacity.
| 250 W LED at 120 V, PF 0.9 | |
|---|---|
| From watts | 2.08 A — seven fit on a 20 A circuit |
| Actual | 2.31 A — only six do |
Manufacturers publish a current per voltage on the spec sheet, and that figure already has power factor in it. Tap the row's A and enter that instead — the chip in force is the filled one. Switching units deliberately does not convert the number you already typed — a converted figure would look authoritative while being invented.
Once any row is entered in amps, totals read VA rather than W, because A × V is apparent power.
Load, DMX, Network and Color each carry a Copy control that puts what is on screen onto the clipboard as plain text — the rig and how it splits, the address and the switches that set it, the network and who gets which address. Paste it into a message, a note, or the paperwork.
The text says exactly what the screen says, including the parts the app is careful about: totals read VA rather than W if anything was entered in amps, a split claims to be the fewest possible only when that was proved, and a DMX line names which switch convention it assumes.
Nothing is stored. The copy happens when you press the button and the app keeps no record of it.
A theatre is dark and loud, so some of this app answers through your hand. Flicking a DIP switch, changing a unit or picking a fixture gives a short tap. Going over a limit gives a warning, and coming back under one gives a different pulse — so you can pull fixtures off an overloaded circuit while looking at the rig rather than at the phone, and feel the moment it comes good.
Ordinary typing and scrolling stay silent on purpose: feedback on everything is the same as feedback on nothing. To turn all of it off, use Settings → Sounds & Haptics → System Haptics — the app does not keep a separate switch for it.
The icon at the top right of any screen sets the appearance: match your phone, always light, or always dark. A theatre is dark at two in the afternoon, so following the phone alone is not much use.
The circular arrow beside the appearance icon clears every field on that screen back to its own defaults — a fresh rig on Load, a fresh network on Network, and so on. It asks first, because nothing in this app is saved between launches: there is no undo for it.
It only clears the screen you are looking at. Load, DMX, Network, Color and Beam do not share anything, so resetting one leaves the other four exactly as you left them.