Electricity Units to Bill Calculator

Why 320 units costs way more than 300 — slab boundaries explained

Domestic electricity tariffs in Pakistan price consumption in ascending slabs: your first block of units (commonly the first 100) is charged at the cheapest rate, the next block at a noticeably higher rate, and so on up through progressively higher brackets. Cross a slab boundary and the additional units beyond that boundary get charged at the new, higher rate — but under several DISCO tariff structures, crossing certain specific thresholds can also shift your entire consumer category, which can retroactively reprice far more of your bill than just the extra handful of units you actually used beyond the line. This is the underlying mystery behind bills that jump disproportionately after just a single hot week of extra air conditioning use.

Decoding the confusing extra lines on your bill

Beyond the basic slab-priced energy charge itself, several additional line items typically appear: FPA (Fuel Price Adjustment) is a monthly correction that reflects the actual real-world cost of fuel used in electricity generation that month, and it can swing meaningfully month to month — sometimes adding a substantial amount, occasionally even working in the consumer's favor as a small credit. GST applies at the standard general sales tax rate calculated on the energy charge portion. Electricity duty, TV licence fee, and various neighbourhood or municipal charges typically ride along as smaller fixed line items regardless of consumption.

This is exactly why the calculator deliberately keeps the tax percentage and fixed charges fields fully editable rather than attempting to guess or hard-code them — your own actual bill's specific numbers are the only reliable ground truth, since these rates and charges are revised periodically by NEPRA and vary meaningfully between different DISCOs across the country.

Why slab boundaries matter — indicative example

Practical, actionable ways to drop into a lower slab

Reading your electricity metre partway through the billing month gives you an early, actionable warning: consuming 160 units by day 15 of the month projects to roughly 320 units by month's end — which is exactly the moment to make conscious adjustments rather than discovering the problem only when the bill arrives. The biggest practical levers available to most households are running inverter air conditioners at 26°C rather than colder settings (since compressor cycling behavior is typically the single largest domestic electrical load by a wide margin), shifting heavy appliances like washing machines and ironing to a single consolidated weekly session rather than spreading usage daily, and replacing remaining incandescent or older CFL bulbs with LED alternatives throughout the home.

Staying consciously under the 200-unit or 300-unit slab boundaries can measurably reduce the average per-unit cost across your entire bill, not merely the specific marginal units you managed to save — which is precisely why small, disciplined consumption changes near a slab boundary often produce a disproportionately larger saving on the final total than the same absolute reduction would produce comfortably within the middle of a slab.

Understanding your DISCO's specific tariff structure

Pakistan currently has multiple distribution companies — including LESCO, K-Electric, IESCO, GEPCO, FESCO, MEPCO, PESCO, HESCO, QESCO and SEPCO — and while NEPRA sets broad national tariff policy, small variations in exact rates and fixed charges do exist between different DISCOs and even between different tariff categories (domestic, commercial, industrial, agricultural) within the same DISCO. Because this calculator's default rates are necessarily indicative approximations rather than a live feed of every DISCO's current published tariff, always copy the exact per-unit rates directly from your own most recent bill into the editable fields here for the most accurate possible estimate of your actual next bill.

Tracking consumption trends month over month

A single month's bill tells you what happened, but keeping a simple running note of your monthly unit consumption over 6-12 months reveals patterns a single bill never shows — like exactly how much summer air conditioning adds compared to winter months, or whether a specific appliance purchase visibly shifted your baseline usage upward. That longer-term view makes it far easier to judge whether a given month's bill is a one-off spike worth investigating or simply the expected seasonal pattern repeating itself.

Comparing this estimate against your actual bill

Treat any estimate here as a planning tool rather than a guaranteed final figure — your DISCO's actual bill remains the authoritative source, especially once monthly FPA adjustments and any arrears are added. Use this calculator to catch problems early in the month, then reconcile against the real bill once it arrives.

Also useful if you searched for: electricity bill calculator pakistan, units to bill calculator, lesco bill calculator per unit, electricity unit price in pakistan, k electric bill calculation, bijli bill calculator, electricity slab rates, how to calculate electricity bill from units, fpa in electricity bill, 200 units bill kitna hai.

Frequently asked questions

Related tools