Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
This unit's bill (sq ft method + admin fee)
$155.11
Sq ft allocation method
$151.11
Occupant count allocation method
$152.38
Equal per-unit split
$160.00
Estimated annual recovery, all units
$37,227
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How to use this
- 1Enter master utility bill (monthly) ($).
- 2Enter total units in building.
- 3Enter this unit's square footage.
- 4Enter total building square footage.
- 5Enter this unit's occupant count.
- 6Enter total building occupant count.
- 7Enter rubs admin fee per unit ($).
- 8Read your this unit's bill (sq ft method + admin fee) on the right — it updates as you type.
- 9Hit Share to keep the scenario or send it to someone.
About this calculator
Ratio Utility Billing System (RUBS) lets owners of master-metered buildings recover utility costs from tenants without installing submeters, by allocating the bill using a formula based on square footage, occupant count, or unit count rather than actual measured usage. This calculator applies the three common allocation methods to a master bill so you can compare how much each unit would owe and how much total recovery you'd see, then estimate what installing real submeters might change. Many states and cities regulate RUBS closely — some cap the admin fee, require specific disclosure, or ban RUBS for water in favor of submetering — so check local rules before implementing.
Worked example
Using the values the calculator loads with:
Inputs
- Master utility bill (monthly): 3200 $
- Total units in building: 20
- This unit's square footage: 850
- Total building square footage: 18000
- This unit's occupant count: 2
- Total building occupant count: 42
- RUBS admin fee per unit: 4 $
Results
- This unit's bill (sq ft method + admin fee): $155.11
- Sq ft allocation method: $151.11
- Occupant count allocation method: $152.38
- Equal per-unit split: $160.00
- Estimated annual recovery, all units: $37,227
What each field means
Inputs
- Master utility bill (monthly) ($)
- The master utility bill (monthly) used in the calculation, measured in $. Starts at 3200 $ so you have a working example on load.
- Total units in building
- The total units in building used in the calculation. Starts at 20 so you have a working example on load.
- This unit's square footage
- The this unit's square footage used in the calculation. Starts at 850 so you have a working example on load.
- Total building square footage
- The total building square footage used in the calculation. Starts at 18000 so you have a working example on load.
- This unit's occupant count
- The this unit's occupant count used in the calculation. Starts at 2 so you have a working example on load.
- Total building occupant count
- The total building occupant count used in the calculation. Starts at 42 so you have a working example on load.
- RUBS admin fee per unit ($)
- The rubs admin fee per unit used in the calculation, measured in $. Starts at 4 $ so you have a working example on load.
Results
- This unit's bill (sq ft method + admin fee)
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Sq ft allocation method
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Occupant count allocation method
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Equal per-unit split
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Estimated annual recovery, all units
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Which allocation method is fairest?
Square footage is most common and courts generally view it as defensible since larger units plausibly use more water and utilities. Occupant-based allocation tracks actual usage drivers better for water specifically but requires verifying and updating occupant counts, which creates more administrative and dispute risk.
Is RUBS legal everywhere?
No — several states and cities restrict or ban RUBS for certain utilities (especially water), require specific tenant disclosures in the lease, or cap the admin fee. California, for example, has specific submetering and billing requirements; always verify your state and local ordinance before rolling out RUBS.
How much can I recover with RUBS vs actual submetering?
RUBS typically recovers 70-90% of what true submetering would, since it's an allocation formula rather than measured usage, but it costs far less to implement — no meters, no separate utility accounts. Submetering costs more upfront (commonly $200-$400 per unit installed) but ties billing directly to actual use and often reduces consumption because tenants see a direct cost link.
Does RUBS reduce my water and sewer expense line?
It shifts the expense from your P&L to tenant billback revenue, but total building consumption doesn't necessarily drop unless tenants can see and control their own usage — RUBS with an allocation formula gives tenants little individual incentive to conserve compared to a true submeter reading their actual usage.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Submetering / RUBS Utility Allocation Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/rubs-utility-allocation
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/rubs-utility-allocation" target="_blank" rel="noopener">Submetering / RUBS Utility Allocation Calculator — RevenueLab</a> (2026).</p>
Source: [Submetering / RUBS Utility Allocation Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/rubs-utility-allocation) (2026).