Summer 2026 AC Bill: How to Split Electricity Fairly with Flatmates (India)

Flatmate electricity bill split with AC rooms and non-AC rooms

It's April in Delhi. The bill that was ₹2,800 in March is now ₹8,400. Four flatmates. Two have AC in their rooms. One works from home with his AC on 10 hours a day. One only sleeps in her AC-cooled room and spends evenings in the living room. Two don't have AC at all — one is away visiting parents for half the month.

How do you split this?

"Equal split" feels wrong. "Each pays for their own AC" is technically fair but mathematically impossible — you don't have sub-meters. "AC users pay 80%, non-AC pay 20%" is a vibe, not a number.

This is the definitive guide. Real slab tariffs for the cities most Indians rent in, three fair split methods with worked examples, and a practical workflow using Niptao so you log this once a month and move on.

Why summer electricity bills are disproportionate

Before getting into the split, it helps to see the scale of the problem.

A 1.5-ton 3-star split AC running 8 hours a day draws about 1.6 kWh/hr. That's 12.8 units a day, or 384 units a month. Multiply across two ACs in a four-flatmate flat and you've added roughly 770 units to the base flat consumption.

At Delhi's 2026 slab tariffs, that extra 770 units costs about ₹7,300 — nearly triple the non-AC months. Mumbai: ₹9,500. Bangalore: ₹8,100. Hyderabad: ₹6,900.

When bills triple without a fair-split rule in place, quarterly roommate WhatsApp groups turn into courtrooms.

The three methods flatmates actually use

Method A — Equal split

Everyone pays equally, regardless of who used the AC.

Works when: everyone has an AC, everyone works similar hours, lifestyles are comparable.

Breaks when: some rooms have AC and others don't, or usage patterns diverge drastically (one WFH, two office-going, one travelling).

Method B — Proportional by appliances

Each flatmate pays a share based on the wattage × hours of their personal appliances, with common-area usage (fridge, fan, lights, router) split equally.

Worked example: monthly bill ₹8,400.

Step 1 — estimate per-room AC consumption:

Room	AC	Usage	Monthly units	Rupees @ ₹8/unit avg
A (Rohan, WFH)	1.5 ton 3★	10 hr × 30 = 300 hr	~480	₹3,840
B (Sneha, sleeps only)	1.5 ton 5★	7 hr × 22 = 154 hr	~185	₹1,480
C (Arjun, no AC)	—	—	0	₹0
D (Priya, travelling half)	—	—	0	₹0

Step 2 — Common area (fridge, router, fans, lights, geyser, washing machine, kitchen): total bill minus AC attributable = ₹8,400 − ₹3,840 − ₹1,480 = ₹3,080. Split 4 ways = ₹770 each.

Step 3 — Final per-flatmate:

Flatmate	AC	Common	Total
Rohan	₹3,840	₹770	₹4,610
Sneha	₹1,480	₹770	₹2,250
Arjun	₹0	₹770	₹770
Priya	₹0	₹770	₹770
Total	₹5,320	₹3,080	₹8,400 ✓

Works when: you can agree on per-appliance hours. Works very well for flats where AC usage is wildly different.

Breaks when: lifestyle changes month-to-month (someone starts WFH, another goes on a trip). You need to re-estimate every month.

Fix for drift: log hours weekly on a shared Niptao note, not from memory at month-end.

Method C — AC surcharge

Equal split for the base bill (what the bill would have been without ACs), plus a fixed monthly surcharge from AC-having rooms to cover the delta.

Worked example:

Pre-AC months (Jan, Feb): avg bill ₹2,800. Equal 4-way split: ₹700 each.
Assume the base stays at ₹2,800 in April.
AC delta: ₹8,400 − ₹2,800 = ₹5,600, attributable to the two AC rooms.
Assume Rohan's 1.5 ton 3★ at 10 hr/day produces 3× more load than Sneha's 1.5 ton 5★ at 7 hr/day → split the delta 75/25.

Flatmate	Base (equal)	AC surcharge	Total
Rohan	₹700	₹4,200	₹4,900
Sneha	₹700	₹1,400	₹2,100
Arjun	₹700	₹0	₹700
Priya	₹700	₹0	₹700
Total	₹2,800	₹5,600	₹8,400 ✓

Works when: you want a simple recurring rule ("Rohan pays ₹4,200 extra every summer month, Sneha ₹1,400"), not a fresh calculation each time.

Breaks when: usage varies month-to-month. Or when Sneha goes to Goa for two weeks and feels she shouldn't be paying ₹1,400 that month.

State-by-state slab tariffs (April 2026)

Electricity in India is state-regulated. The "per unit" price depends on your monthly consumption slab. A household at 200 units pays a very different per-unit rate than one at 800 units.

Current residential (non-subsidised) slab tariffs, approximate:

State / City	0–100 units	101–200	201–300	301–400	401+
Delhi (BRPL/BYPL/TPDDL)	₹3.00	₹4.50	₹6.50	₹7.00	₹8.00
Mumbai (Adani/Tata Power)	₹3.40	₹6.30	₹8.90	₹12.20	₹13.40
Bangalore (BESCOM)	₹4.55	₹6.45	₹7.65	₹8.30	₹9.60
Hyderabad (TSSPDCL)	₹1.95	₹3.10	₹4.80	₹7.20	₹8.50
Chennai (TANGEDCO)	₹4.50	₹4.50	₹6.00	₹8.00	₹9.00
Kolkata (CESC)	₹5.45	₹6.10	₹7.00	₹7.80	₹8.50
Pune (MSEDCL)	₹3.40	₹7.40	₹10.30	₹11.50	₹12.50
Noida / Ghaziabad (UPPCL)	₹4.90	₹5.40	₹6.50	₹6.50	₹7.00

Why the slab matters for flatmates: when four of you share a flat, your monthly consumption is usually already in the top slab (Mumbai, Pune, Delhi). So an incremental AC unit costs you the top-bracket rate — which is why the delta from non-AC months looks eye-watering.

The sub-metering shortcut — smart plugs

If you're in the "one AC per flatmate" configuration and the fight is recurring, it's worth spending ₹1,500 on a smart plug with energy monitoring (Wipro, TP-Link Tapo, Amazon Basics). Plug the AC into it, read the kWh consumed at month-end.

Then the per-AC contribution becomes exact: kWh × top-slab per-unit rate. No more negotiation.

This only works for split ACs with single-plug outdoor units — for window ACs it's even cleaner, for central/ducted AC it doesn't help.

What about the geyser, fridge, washing machine?

These are common-area appliances that everyone uses. Standard practice:

Fridge (~40 units/month) — always common, split equally.
Geyser (~60–80 units/month in winter, 10–20 in summer) — common, split equally. Tiny fights happen about who takes the longest showers.
Washing machine (~10–15 units/month) — common, split equally, unless someone has a dedicated machine in their room (rare).
Kitchen / induction / microwave — common, split equally.
Lights, fans, chargers — common, split equally.

The only appliances that justify a per-person breakdown are ACs, gaming PCs with heavy usage, personal space heaters, and personal water heaters (e.g. a dedicated geyser in someone's attached bathroom).

The Niptao workflow for summer months

Here's what a "bills committee of one" looks like in practice using Niptao:

Day the bill arrives: one flatmate logs in, opens the flat's group, taps "Add expense".
Enters ₹8,400, date = bill date, category = Utilities.
Picks split type Exact amounts (not equal, not percentage).
Types in the four rows: ₹4,610 / ₹2,250 / ₹770 / ₹770 — sanity-checked against the table above.
Taps save. Niptao sends a push notification to each flatmate: "Rohan added ₹4,610 owed to Rohan from you."
Each flatmate taps Pay in their app → UPI chooser opens with Rohan's VPA and amount pre-filled → one tap.

The iOS settle flow copies VPA + amount to clipboard instead of deep-linking (because Safari refuses custom URI schemes reliably). Android gets the OS chooser — GPay/PhonePe/Paytm/BHIM all selectable in one tap.

Takes about 90 seconds end to end for the bill-logger, and 20 seconds per flatmate to settle. No WhatsApp voice notes. No "can I pay you next week?". No screenshots of the bill debated in group chat.

A quick word on subsidies

Most states have subsidised slabs for low consumption (up to 100 or 200 units/month). A four-flatmate flat with two ACs almost never qualifies. Don't factor in subsidy when estimating — you're paying top-slab rates and need to plan for them.

Exception: Delhi's 200-unit free scheme (applies if you consume ≤200 units/month, rare for shared flats). Karnataka's Gruha Jyothi (up to 200 free units for domestic connections). Tamil Nadu's 100-unit free (commercial/residential varies).

What if one flatmate refuses to pay?

Rare but happens. The social contract: whoever pays the bill bears the full cost until settled. If a flatmate stalls for more than a week, Niptao sends gentle nudge notifications — the bill amount sits visibly in their balance row so it's hard to forget.

If it becomes a pattern, the conversation usually isn't about the ₹2,250 electricity bill — it's about whether the flat arrangement is still working.

Quick calculator — what's your AC costing you?

Rough formula for a single AC:

Monthly units ≈ (tonnage × 850 × hours per day × days) / (efficiency factor)

Where efficiency factor is:

3-star: 1.1
4-star: 1.3
5-star: 1.5
Inverter (5★): 1.7

Worked examples

1.5 ton, 3★, 8 hr/day, 30 days: (1.5 × 850 × 8 × 30) / 1.1 = 278 units
1.5 ton, 5★ inverter, 8 hr/day, 30 days: (1.5 × 850 × 8 × 30) / 1.7 = 180 units
2 ton, 4★, 10 hr/day, 30 days: (2 × 850 × 10 × 30) / 1.3 = 392 units

Multiply by your top-slab rate from the table above for the rupee cost.

FAQ

Is it fair to charge the AC-haver more than the non-AC flatmates?
Yes. Electricity is a measurable resource — not all flatmates consume equally. Method B and C above are both industry-standard in Indian shared-housing norms. Method A (equal split) is only fair when consumption really is equal.

What if we don't know who uses what?
Start with equal split and revisit after 30 days. If the summer bill more than doubles the winter bill, switch to Method C with a fixed AC surcharge.

Is sub-metering legal in rented flats?
Yes, as long as you don't modify the main meter. Plug-level smart monitors (Wipro/TP-Link) are fully legal and tenant-installable.

Does the landlord cover common-area ACs?
Only if specified in the agreement — most standard rental contracts assign electricity to the tenant.

Can Niptao handle recurring monthly bills automatically?
Not currently — each bill is logged manually. A "recurring expense" feature is on the roadmap.

TL;DR

For equal-lifestyle flats, Method A (equal split) is fine. Log the bill once, everyone settles, move on.
For mixed-AC flats, Method B (proportional) is fairest but needs monthly estimation.
For stable summers, Method C (surcharge) is low-overhead and readable.
Use smart plugs if AC-disputes are recurring.
Use Niptao to collapse the "who owes what by when" arithmetic into a single screen everyone can pay from in 20 seconds.

The summer bill is never fun, but a fair split and a one-tap settlement is the difference between a flat that lasts three years and a flat that breaks up by Monsoon.

Start your flat's Niptao group — free, no signup card, no ads.