Tenant Sub-Meter Calculator
If your landlord reads a private sub-meter and charges a flat ₹10–₹12 a unit, there is no way to tell from that number what the power actually cost. Real tariffs are telescopic — the first slabs are cheap, the fixed charge lands once on the whole building, and the effective rate on a domestic connection is usually far below the top slab. Enter your sub-meter reading and your landlord's rate, and this works out your share of the real DISCOM bill and the exact gap, with a report you can print and hand over.
Why a flat per-unit rate almost always overcharges
A domestic tariff is not one rate. It is a ladder: the first 100 or 200 units are billed at a low rate, the next block a little higher, and only heavy consumption reaches the top slab. On top of that sits a fixed charge that is levied once on the connection — per kW of sanctioned load, not per tenant — plus fuel surcharge and electricity duty as percentages.
Landlords generally pick a single number that covers the worst case and stop thinking about it. Because most of a building's units are consumed in the cheaper slabs, that number is usually well above the connection's real effective rate. A 5 kW domestic connection drawing 700 units a month often works out to ₹7–₹8 a unit all-in — so a flat ₹11 is a 40%+ markup on power the landlord is only passing through.
How your fair share is calculated
Energy and every per-unit or percentage charge are apportioned pro-rata on units. That is the even-handed method precisely because the tariff is telescopic — the cheap opening slabs belong to the connection as a whole, so no tenant gets to claim them while a neighbour absorbs the expensive ones. Re-running the slabs on your units alone would let whoever is metered "first" pay a fraction of the true cost.
The fixed and demand charges are different: they exist whether or not you switch anything on, so the default here splits them equally across the sub-meters on the connection. If your arrangement shares them by consumption instead, switch the last dropdown. Everything else — fuel surcharge, electricity duty, minimum charge top-ups — is computed by the same engine behind the main bill calculator and carried into your share proportionally.
If you do not know the main-meter reading
Leave that field blank and the tool bills your units as though they were the entire connection. That deliberately understates the real cost per unit, because you are no longer sharing the cheap first slabs with anyone — so the overcharge it reports becomes a floor rather than an estimate. If the number is already uncomfortable on that basis, it is worse in reality. Asking your landlord for the main bill for the same month is a reasonable request: you are paying a share of it.
Where you stand
Sub-metering, permitted service charges and whether a landlord may add anything above cost are governed by your State Electricity Regulatory Commission, not by a single national rule, and the position differs meaningfully between states. What is consistent is that reselling power at a profit is restricted almost everywhere, and that a landlord recovering the actual cost plus genuinely incurred expenses is on far firmer ground than one applying a habitual markup.
In practice the numbers settle most of these conversations without anyone invoking a regulation. If they do not, your DISCOM's consumer grievance redressal forum will take a complaint — the complaint helper has the forum and the 1912 national helpline for your state.
This tool computes the tariff cost of your units from published DISCOM rates and apportions it by a stated method. It is an estimate for discussion, not legal advice, and it does not determine what your tenancy agreement or your state's regulations permit. Tariffs, fuel surcharge and duty change through the year; verify against the current tariff order and the main-meter bill before relying on the figures. See how our rates are sourced and verified.