✦ Household Arithmetic
Household
Household
Electricity
Learn how Nepal Electricity Authority (NEA) calculates your electricity bill using slabs, tariff rates, energy charges and fixed fees — step by step.
💡 4 Modules
📝 3 Examples
✏️ 9 Questions
🇳🇵 NEA Tariff
💡 Module 01
Introduction to Electricity Bills
⚡ Real Life Math
Why does your
electricity bill change every month?
The more electricity your family uses, the higher the rate per unit you pay! This is called a slab tariff system — Nepal Electricity Authority divides usage into slabs and charges different rates for each.
5
Ampere Slabs
Rs.3
Min. Charge/unit
2078
NEA Tariff Year
Your Home
00248
kWh CONSUMED
Minimum chargeRs. 30
Energy chargeRs. 2,057
Total BillRs. 2,087
Unit (kWh)
1 unit = 1 kilowatt-hour. Running a 100W bulb for 10 hours uses 1 unit. Your meter counts how many units you consume each month.
Slab System
NEA divides consumption into slabs: 0–20, 21–30, 31–50, 51–100, 101–250, 251+ units. Each slab has its own rate per unit.
Bill Components
Your bill = Minimum charge + Energy charge. Energy charge is calculated slab by slab. Extra charges apply for late payment.
🇳🇵 NEA Tariff — 5 Ampere Connection (2078/79)
The Nepal Electricity Authority fixed tariff rates for single-phase 5-Ampere domestic connections. The tariff was fixed at the 140th meeting of the Electricity Regulatory Body in 2078/79.
KWH = Kilowatt Hour = 1 Unit of Electricity
📋 NEA Tariff Rate Table — 5 Ampere Connection
| S.N. | Units Consumed | Rate/Unit (Rs.) | Way of Billing |
|---|---|---|---|
| 1 | 0 – 20 | 0.00 | Minimum charge: Rs. 30 and no energy charge |
| 2 | 21 – 30 | 8.00 | Minimum charge Rs. 30 + 21 to 30 units @ Rs. 8.00 |
| 3 | 31 – 50 | 8.50 | Minimum charge Rs. 30 + 21–30 @ Rs. 8 + 31–50 @ Rs. 8.50 |
| 4 | 51 – 100 | 9.50 | Accumulated from slabs 1–3 + 51–100 @ Rs. 9.50 |
| 5 | 101 – 250 | 9.00 | Accumulated from slabs 1–4 + 101–250 @ Rs. 9.00 |
| 6 | 251 – 400 | 11.00 | Accumulated from slabs 1–5 + 251–400 @ Rs. 11.00 |
| 7 | Above 400 | 12.00 | Accumulated from slabs 1–6 + above 400 @ Rs. 12.00 |
🔄 How Is Your Bill Calculated? — Step by Step
1
Read the Meter
Units consumed = Present reading − Previous reading.
2
Find Which Slab(s) You Fall Into
Calculate cumulative slab charges.
3
Calculate Energy Charge
Multiply units in each slab by its rate and add them.
4
Add Minimum Charge
Add fixed Rs. 30. Total Bill = Minimum Charge + Energy Charge.
5
Extra Charges (if applicable)
2% discount if paid within 7 days. 5% extra if paid after 15th day, etc.
🔢 Module 02
Key Formulas
📐 Formula 1 — Units Consumed
Units Consumed = Present Reading − Previous Reading
Read the electricity meter at end and start of billing period.
📐 Formula 2 — Energy Charge (Slab Calculation)
Energy Charge = Σ (Units in each slab × Rate of that slab)
Example for 85 units: = (20×0)+(10×8)+(20×8.50)+(35×9.50) = 0+80+170+332.50 = Rs. 582.50
📐 Formula 3 — Total Electricity Bill
Total Bill = Minimum Charge (Rs. 30) + Energy Charge
📐 Formula 4 — Discount for Early Payment
Discount Amount = (2 × Total Bill)/100 (if paid within 7 days)
Amount to Pay = Total Bill − Discount Amount
📐 Formula 5 — Extra Charge (Fine) for Late Payment
5% extra if paid from 16th to 30th day: Extra = (5 × Total Bill)/100
10% extra if paid from 31st to 40th day: Extra = (10 × Total Bill)/100
25% extra if paid from 41st to 60th day: Extra = (25 × Total Bill)/100
📝 Module 03
Worked Examples
Example 1 of 3
A meter of capacity 5 ampere is installed in Rambabu's house. Find the electricity bill for the month of Poush 2078 BS given that: Present reading = 42975, Previous reading = 42528. The bill is paid on the 23rd day of the meter reading. How much would Rambabu have to pay?
PR = 42975VR = 42528Payment: 23rd day
✏️ SOLUTION
1
Units consumed = 42975 − 42528 = 447 units
2
Energy charge by slabs: 0+80+170+475+1350+1650+564 = Rs. 4,289
3
Total Bill = 30 + 4289 = Rs. 4,319
4
Paid on 23rd day → 5% extra = Rs. 215.95
✅ Total amount Rambabu pays = Rs. 4,319 + Rs. 215.95 = Rs. 4,534.95
Example 2 of 3
The present reading of Sita's house meter is 3700 and previous reading is 3452. The bill is paid on 5th day from meter reading. Find: (a) Total electricity bill, (b) Amount paid after discount.
PR = 3700VR = 3452Payment: 5th day
✏️ SOLUTION
1
Units = 248
2
Energy charge = Rs. 2,057
3
Total Bill = 30 + 2057 = Rs. 2,087
4
Discount (2%) = Rs. 41.74
✅ (a) Total Bill = Rs. 2,087 | (b) Amount paid after discount = Rs. 2,045.26
Example 3 of 3
Ganesh's electricity meter shows present reading 3044 and previous reading 3003. The bill is paid on the 40th day from meter reading date. Calculate the total amount Ganesh has to pay including the fine.
PR = 3044VR = 3003Payment: 40th day
✏️ SOLUTION
1
Units = 41 units
2
Energy charge = Rs. 173.50
3
Total Bill = 30 + 173.50 = Rs. 203.50
4
Fine (10%) = Rs. 20.35
✅ Total Ganesh pays = Rs. 203.50 + Rs. 20.35 = Rs. 223.85
✏️ Module 04
Solved Questions