How Your TNB Electricity Bill Is Worked Out (RP4)
Every charge on a TNB domestic bill under the RP4 tariff, three bills worked out line by line, and how the 800 kWh relief changes things.
Updated
Your TNB bill is the sum of several small charges, and some of them switch on or off depending on how much you use. This guide walks through the Regulatory Period 4 (RP4) tariff for homes in Peninsular Malaysia, shows three bills worked out line by line and explains the temporary 800 kWh relief. The figures match the Electricity Bill Calculator.
The tariff has been in force since 1 July 2025 and runs to 31 December 2027, according to the Energy Commission (ST). Sabah and Sarawak are supplied by SESB and Sarawak Energy, with their own tariffs, which this calculator does not cover.
What is on the bill
- Energy charge. 27.03 sen per kWh for usage up to 1,500 kWh in the month, and 37.03 sen above that.
- Capacity charge. 4.55 sen per kWh.
- Network charge. 12.85 sen per kWh.
- Retail charge. RM10 a month, waived at or below the threshold.
- Automatic Fuel Adjustment (AFA). Set monthly by ST in sen per kWh, waived at or below the threshold. ST posts a monthly AFA notice on its website. Our examples use +3.61 sen, the October 2026 figure.
- Energy Efficiency Incentive (EEI). A rebate in sen per kWh, taken off every unit. It is 25 sen at 200 kWh or less and falls in steps to 0.5 sen up to 1,000 kWh. Above 1,000 kWh there is none. The band is set by the month's total.
- KWTBB. 1.6% of the charges after EEI, charged when usage is above 300 kWh. It funds renewable energy.
- Service tax. 8% on the part of the bill above the threshold.
The standard threshold for the retail charge, AFA and service tax is 600 kWh a month.
The 800 kWh relief
The government raised the threshold from 600 to 800 kWh for usage from 1 September to 31 December 2026. TNB's announcement says homes using 800 kWh or less in a month do not pay AFA, the retail charge or service tax. The threshold goes back to 600 kWh from 1 January 2027. The calculator picks the threshold from the billing date.
Three bills, worked out
With AFA at +3.61 sen per kWh and a bill dated in October 2026:
| Item | 300 kWh | 450 kWh | 900 kWh |
|---|---|---|---|
| Energy charge | RM81.09 | RM121.64 | RM243.27 |
| Capacity charge | RM13.65 | RM20.48 | RM40.95 |
| Network charge | RM38.55 | RM57.83 | RM115.65 |
| Retail charge | RM0.00 | RM0.00 | RM10.00 |
| AFA | RM0.00 | RM0.00 | RM32.49 |
| EEI rebate | −RM67.50 | −RM65.25 | −RM9.00 |
| KWTBB | RM0.00 | RM2.16 | RM6.25 |
| Service tax | RM0.00 | RM0.00 | RM4.56 |
| Total | RM65.79 | RM136.86 | RM444.17 |
At 300 kWh the EEI is 22.5 sen on every unit, which takes RM67.50 off. At 450 kWh the band changes to 14.5 sen. At 900 kWh the EEI is only 1 sen per unit, and because usage is above 800 kWh the retail charge, AFA and service tax apply.
The same 900 kWh in February 2027, when the threshold is back at 600 kWh, comes to RM451.70. The service tax alone rises from RM4.56 to RM12.09.
Why one kWh can cost RM5 or RM50
Bills do not rise smoothly, because rebates and charges change at set points. With the October 2026 rules:
- 300 kWh costs RM65.79, but 301 kWh costs RM71.66. The 1.6% KWTBB starts above 300 kWh and the EEI band changes.
- 350 kWh costs RM83.33, and 351 kWh costs RM97.82, a jump of RM14.49 for one unit, because the EEI falls from 21 to 17 sen on every unit.
- 800 kWh costs RM328.62, and 801 kWh costs RM380.99. Under the temporary relief the retail charge, AFA and service tax all switch on just above 800 kWh.
In February 2027, with the threshold back at 600 kWh, 600 kWh costs RM215.98 and 601 kWh costs RM258.03.
Cutting the bill
Look at the band edges. The EEI rebate drops in steps, and the extra charges start above the threshold, so the first kWh above a band can cost more than it looks. The myTNB tariff page has TNB's own tariff table and calculator, and the myTNB app shows your usage.
Solar: a simple payback
Solar savings depend on your roof, your usage and the system. A simple check divides the system cost by the yearly saving. If a system costs RM15,000 and cuts your bill by RM150 a month, the yearly saving is RM1,800 and the payback is about 8.3 years. Over 25 years the net saving is RM30,000. This ignores panel ageing and tariff changes, so treat it as a first look. Run your own numbers in the Solar Savings Calculator.
The rates follow our rates files. Your TNB bill is final, and the AFA changes every month.