Why KSEB Halves Your Units Before Applying Slabs
Kerala's slabs are written per month, but most domestic meters are read every two months. KSEB bridges the
two by working out the bill for the monthly average and doubling it, along with the fixed charge.
Worked example: a single-phase home with a two-month reading of 480 units is treated as 240
units a month. That falls in the telescopic range, so the energy charge is (50 × ₹3.35 + 50 × ₹4.25 + 50 × ₹5.35
+ 50 × ₹7.20 + 40 × ₹8.50) × 2 = ₹2,695. The 201–250 band's fixed charge of ₹160 a month adds
₹320, so the bill is ₹3,015 before duty and surcharges.
Averaging is why a two-month bill can feel cheaper than one heavy month: a 400-unit summer month followed by
an 80-unit month averages to exactly 240.
KSEB Domestic Rates From 1 April 2025 to 31 March 2027
The Kerala State Electricity Regulatory Commission (KSERC) set these LT-1(A) domestic rates in its order of
5 December 2024. The same order raised tariffs once on 5 December 2024 and again on 1 April 2025, and approved no
revision for 2026-27, so the rates below apply until 31 March 2027.
Up to 250 units a month: telescopic
| Monthly units | Rate per unit | Fixed charge, single phase | Fixed charge, three phase |
|---|
| 0 – 50 | ₹3.35 | ₹50 | ₹130 |
| 51 – 100 | ₹4.25 | ₹85 | ₹175 |
| 101 – 150 | ₹5.35 | ₹105 | ₹205 |
| 151 – 200 | ₹7.20 | ₹140 | ₹215 |
| 201 – 250 | ₹8.50 | ₹160 | ₹235 |
Above 250 units a month: one rate on every unit
| Monthly units | Rate on all units | Fixed charge, single phase | Fixed charge, three phase |
|---|
| Up to 300 | ₹6.75 | ₹220 | ₹240 |
| Up to 350 | ₹7.60 | ₹240 | ₹250 |
| Up to 400 | ₹7.95 | ₹260 | ₹260 |
| Up to 500 | ₹8.25 | ₹285 | ₹285 |
| Above 500 | ₹9.20 | ₹310 | ₹310 |
Published summaries of the order differ by a few rupees on the fixed charges above 250 units. If your bill
shows a different fixed charge, type it into the calculator so the total matches.
BPL concession: BPL households with a connected load up to 1,000 watts that use no more
than 40 units a month pay ₹1.50 a unit and no fixed charge.
Crossing 250 Units a Month
The step from telescopic to flat-rate billing is where KSEB bills jump. A two-month reading of 500 units
averages exactly 250 a month and costs ₹3,185 on single phase. At 502 units the average is
251, every unit is charged ₹6.75 and the fixed charge moves to the ₹220 band, so the bill becomes
₹3,828.50. Two extra units add ₹643.50.
The flat-rate bands have smaller steps of their own at 300, 350, 400 and 500 units a month, because each band
re-prices every unit, not just the extra ones.
Time-of-day billing above 250 units
Under the same order, homes using more than 250 units a month can be billed on time-of-day rates. The flat
rate for your band is the base: use between 6 am and 6 pm is charged at 90% of it, 6 pm to 10 pm at 125% and
10 pm to 6 am at 100%. A 600-unit two-month bill with 40% of use in the day and 30% in the evening peak costs
₹4,191.75 in energy instead of ₹4,050 at the flat rate. If your bill shows ToD readings, tick the ToD box in the
calculator and enter your own split.
What Rooftop Solar Does to a KSEB Bill
Solar helps twice on a Kerala bill. It removes units, and when it pulls the monthly average back under 250
it also moves you from the flat rate back to the cheaper telescopic slabs and a lower fixed-charge band.
Example, Thrissur: a single-phase home using 560 units in two months averages 280 a month
and pays ₹4,220 (560 × ₹6.75 plus ₹440 fixed). Thrissur gets about 4.2 peak sun hours, so a 2 kW system makes
about 404 units in two months. The net 156 units average 78 a month, which brings the bill down to about
₹743: ₹573 energy and ₹170 fixed. That is roughly ₹3,477 saved each billing cycle.
KSEB can set a prosumer's fixed-charge band differently from the net units, so treat the fixed charge after
solar as approximate. Size the system for your whole year with the
solar system size calculator.
Charges outside this calculator
- Electricity duty: a state levy added to the energy charge on the bill.
- Fuel surcharge: a per-unit adjustment notified from time to time.
- Meter rent: a small monthly amount that depends on the meter type.
Orders and Documents Used
- KSERC tariff order of 5 December 2024 on KSEB Ltd's tariff petition: LT-1(A) domestic rates
for 5 December 2024 to 31 March 2025 and for 1 April 2025 to 31 March 2027, with no revision approved for
2026-27. Available from the Kerala State
Electricity Regulatory Commission.
- KSEB tariff revision circular for 1 April 2025 to 31 March 2027: applying the revised
rates to all consumers and keeping the BPL rate of ₹1.50 a unit with no fixed charge. See
KSEB.
Rates checked on 9 October 2026.
