GEPCO Bill Calculator — Estimate Your Bill Before It Arrives

A GEPCO bill calculator turns your units into a rupee figure using the current NEPRA tariff. Enter units consumed, pick your consumer category, add your sanctioned load, and it returns the energy charge, fixed charge, duty, GST and TV fee as separate lines. It is an estimate for planning, not the amount you owe.

The three inputs, and where each one lives

Most estimates go wrong at the input stage, not the maths.

• Units. Present Reading minus Previous Reading, from the Meter Info box on your last bill. If you’re estimating mid-cycle, read the meter yourself and subtract the Present Reading printed on last month’s bill.
• Category. Printed in the Consumer Detail box as Protected or Unprotected. Do not guess this. It is the single biggest swing in any estimate — the same 190 units can differ by several thousand rupees between the two.
• Sanctioned load. The San Load field on your bill, in kW. Most single-phase homes show 1 to 5. This drives the fixed charge.

Two optional inputs make the estimate much closer: the FPA and QTA rates. Both are printed as rupees-per-unit on your last bill. Copy them rather than leaving them blank — an estimate without them will come out low.

Reading your meter mid-cycle

This is where a calculator earns its place, and it’s the use almost nobody explains. Say your reading date is the 11th and today is the 25th. Fourteen days have passed.

1. Read your meter now. Subtract the Present Reading from your last bill. That’s units used so far.
2. Divide by days elapsed. That’s your daily average.
3. Multiply by the full cycle length, roughly 30 days.

Worked: last Present Reading 59,341. Today the meter shows 59,530. That’s 189 units over 14 days, or 13.5 per day. Projected over 30 days: about 405 units. Now put 405 into the calculator. If the result is uncomfortable, you still have two weeks to change it.

Catching a slab crossing before it happens

Because every unit is billed at the rate of the slab your total lands in, the cost of crossing a boundary is not the cost of the extra units. It is a rate increase applied backwards across everything you have already used.

Run your projection through the calculator, then run it again at the number just below your next boundary. The difference is what those last few units actually cost you.

A household projecting 410 units is not paying for 10 units above 400. It is paying a higher rate on all 410. Pulling back to 395 is worth far more than the fifteen units suggest.

If your projection lands within about 20 units of 200, 300, 400 or 500, that fortnight is worth watching closely. Shifting the water motor, the iron and one AC hour is usually enough.

What no calculator can see

An estimate covers the energy charge and the standard levies. Your printed bill carries rows that exist only in GEPCO’s billing system:

• Arrears — an unpaid balance from earlier months, added on top
• Installment — a scheduled portion of an old balance
• Outstanding Units — carried over when the previous cycle was billed pro-rata
• Subsidies — applied against your category and history
• Adjustments and W.E Credit — corrections issued by the system
• Deferred Amount — any sum formally postponed
• L.P. Surcharge — if a previous bill went past its due date
• Meter rent — where it applies to your connection

Your protected status also depends on six months of billing history that no public tool has access to.

This is why an estimate and a bill rarely match to the rupee. When you need the exact figure, Check Bill and read the Grand Total.

Using it backwards to check a bill you already have

The calculator works just as well in reverse.

Take the units printed on your bill, enter them with your real category and load, and add the FPA and QTA rates from the bill itself. Compare the result to the printed total.

A gap of a few hundred rupees is normal — rounding, meter rent, small adjustments.

A gap of several thousand is worth investigating. Check the Arrears row first, since that accounts for most large differences. If arrears are zero and the gap remains, check the Category field. A domestic connection billed on an unprotected code when it should be protected produces exactly this pattern.

Turning appliances into units

If you have no meter reading and no bill, you can still get a workable number. Watts × hours ÷ 1,000 = units per day.

A household running one non-inverter AC for eight hours through July adds roughly 380 units to whatever it uses the rest of the year. That is the entire explanation for most summer bill shocks in Gujranwala and Sialkot, and the same maths tells you what an inverter unit would save.

Why two calculators give different answers

Three reasons, and they are all worth knowing.

• Slab method. Many tools add the blocks together — the first 100 at one rate, the next 100 higher, and so on. For unprotected domestic consumers that is not how the notified schedule works, and it produces an estimate several thousand rupees below the real figure at higher consumption.
• Stale rates. Several published calculators still apply 17% GST and superseded per-unit rates.
• Live adjustments. FPA changes monthly. The quarterly adjustment can be a charge or a credit, and there have been quarters where it reduced bills across all DISCOs. A tool with those fields hard-coded to zero will be wrong every month.

The fix is the same in all three cases: take the FPA and QTA figures off your own bill and enter them.

Common questions