Three defensible answers to the same question
Run the defaults and the wood shop pays $745.59 under a floor area split, $533.60 under a headcount split and $949.33 under a metered split. Nobody is cheating. Floor area says you pay for the space you occupy, headcount says you pay for the people you bring, and metering says you pay for what you actually drew. All three are honest, and the gap between the best and worst of them for that one occupant is $415.73 a month, or $4,988.76 over a year.
The consequence is that the argument is decided before the bill arrives, by whoever writes the agreement, and pretending otherwise just relocates the argument to the end of the month. Pick a basis, write it down, and note which bill it applies to — the right basis for electricity in a shop full of machines is not the right basis for internet.
The fixed charge is not caused by anyone
Look at an electricity bill and a meaningful slice of it is not consumption at all: a service charge, a meter fee, a minimum, sometimes a demand charge. That money arrives whether the building ran or sat dark. Push it through a metered split and you have charged the heaviest user for the privilege of having a meter, which is not what the meter measures.
This page pulls the fixed share out first and spreads it separately, either evenly or by floor area, and only divides the remainder on the basis you chose. The same logic is why the laundromat calculator insists on separating the utility cost that moves with cycles from the utility cost that runs anyway: they are different kinds of money and blending them makes both figures useless.
Common area use breaks a metered split
Submeters cover the studios. They do not cover the corridor lights, the kitchen, the server cupboard or the compressor that everyone uses and nobody switched on. Those units are real and somebody pays for them, and if you simply divide the bill in proportion to submeter readings, the answer is that the heaviest users pay for the corridor in proportion to how hard they work. At the defaults, 260 common units out of 4,610 pull $83.02 out of the metered pool and spread it the same way the fixed charge is spread.
If your building has no common draw worth counting, set that field to zero and the metered column becomes a straight proportion. If it does, guessing the number is better than ignoring it, and a clamp meter on the common circuit for a week is better than guessing.
Reconciling to the cent, and why it matters
Each column here uses the largest remainder method: everyone gets the whole cent floor of their exact share, and the cents left over go to the largest fractional parts. That is why two occupants with identical numbers can differ by a penny. The alternative, rounding each share independently, leaves the column a few cents away from the bill, and on a charge you re-issue monthly that discrepancy compounds into a figure somebody queries. If you are splitting a one-off rather than a recurring charge, the bill split calculator and the itemised receipt splitter handle that shape.
For the rent underneath the utilities rather than the utilities themselves, the load factor calculator converts a quote into a cost per seat, and the sublease carry calculator handles the case where you hold the lease and someone else occupies part of the floor. The rate side of the bills themselves is on the electricity bill calculator and the water bill calculator.
Questions people ask
Which basis is fairest for splitting electricity in a shared workshop?
It depends on what dominates the draw. Where the load is machines, metered use tracks cause most closely and floor area tracks it worst, because a 340 square foot bench operation with a laser cutter can outdraw a 1,150 square foot storage bay. Where the load is lighting and climate, area tracks cause better than a meter would, because a bigger space needs more of both regardless of who is in it. The practical answer in mixed buildings is to meter what is worth metering and spread the rest by area, which is what the fixed and common pools on this page do.
Why does the metered column not simply follow the submeter readings?
Two corrections stand between the readings and the bill. The fixed service charge is not consumption and is spread separately. And the common areas draw units that no submeter attributes to anyone, so their cost is pulled out of the metered pool and spread as well. Without those two steps the submetered occupants absorb the corridor and the standing charges in proportion to their own use, which is a real effect and a real source of disputes when someone works it out.
Do the columns really add to the bill exactly?
Yes, by construction. The fixed share and the variable share are derived so that one is the remainder of the other rather than being rounded separately, and each is divided using the largest remainder method, which allocates whole cents and hands the leftovers to the biggest fractions. The totals row is not a rounded sum of rounded numbers; it is the bill itself. That is worth caring about on a recurring charge, where a few cents of drift a month becomes a visible discrepancy over a year.
Can I charge my studio mates more than the bill to cover my trouble?
That is not an arithmetic question and this page will not answer it. Whether you may recharge a utility at all, whether you may add anything to it, and whether the arrangement makes you a landlord in the eyes of your own lease are questions for your lease, your landlord and a lawyer, and the answers vary by where you are and by what you signed. Work out the split here, then take the arrangement to someone qualified before you put it in writing.
What about the internet, or a bill everyone uses equally?
Run it as a separate bill with the fixed share set to 100 percent, which spreads the whole thing evenly or by area depending on the second setting. Bundling a connection charge into an electricity split hides the fact that the two have completely different causes, and once they are bundled nobody can check either. One bill at a time is slower and it is the only version anyone can audit.