How to Calculate ZESCO Electricity Units (2026)

When you buy ZESCO prepaid electricity tokens, the number of units (kWh) you receive depends on how much you have already consumed that month. ZESCO uses a block tariff system where the price per unit increases as your consumption rises.

This guide explains exactly how the system works for residential prepaid customers. Use our ZESCO electricity calculator to see the exact cost or units for any amount instantly.

Note: The rates in this guide apply to residential prepaid electricity only. ZESCO has separate tariff structures for commercial, industrial, and other customer categories.

How the block tariff works

ZESCO does not charge a flat rate per unit. Instead, your consumption each month is divided into blocks (bands), and each block has its own price per unit. The first block is the cheapest, and each subsequent block costs more.

The current residential prepaid tariff bands for 2026:

This means your first 100 units each month are always at the cheapest rate. Only the units above 100 move into the next band, and so on.

Worked example: buying K200 of electricity

Let us calculate how many units you get for K200, assuming you have not bought any electricity this month yet:

Step 1: First 100 units at K0.42

100 units x K0.42 = K42.00
Remaining: K200 - K42 = K158.00

Step 2: Next 100 units at K1.19

100 units x K1.19 = K119.00
Remaining: K158 - K119 = K39.00

Step 3: Remaining money at K2.89

K39.00 / K2.89 = 13.5 units

Total

Total units = 100 + 100 + 13.5 = 213.5 units for K200

Key insight: The first K42 buys you 100 units. The next K119 buys another 100. But the remaining K39 only buys 13.5 units because you are now in the third band. This is why electricity feels more expensive the more you use.

How the monthly reset works

Your consumption bands reset on the 1st of each month. This means:

• On 1 January, your consumption counter resets to zero

• Your first purchase of the month starts at the cheapest band

• Each subsequent purchase in the same month continues from where you left off

• Units purchased in December do not carry over to January's band calculation

Tip: Buying all your electricity in one large purchase at the start of the month gives the same result as buying it in several smaller purchases throughout the month. The total cost is the same because bands are cumulative.

VAT and excise duty

Residential ZESCO prepaid electricity is currently zero-rated for VAT and excise duty. The tariff rates shown above are the all-inclusive cost per unit - no additional tax is added on top for residential customers.

What affects your electricity consumption?

A basic household (lights, fridge, TV, phone charging, weekly ironing) uses roughly 80-120 units per month - comfortably within the first two bands. Adding an air conditioner or geyser is what pushes most homes into the expensive third and fourth bands.

Frequently asked questions

Does buying electricity in smaller amounts save money?

No. The block tariff is cumulative per month. Whether you buy K500 in one go or K100 five times, you pay the same total. ZESCO tracks your monthly consumption regardless of how many purchases you make.

Why did I get fewer units than last time for the same amount?

Because you had already consumed units earlier in the month. Your previous purchases pushed you into a higher band, so the next purchase starts at the more expensive rate. At the start of a new month, you will get more units again because the bands reset.

Do these rates apply to commercial properties?

No. These are residential prepaid rates only. ZESCO has separate tariff structures for commercial, industrial, mining, and other customer categories. Contact ZESCO directly for commercial rates.

For the full rate table, see our 2026 ZESCO tariff bands guide. To see exactly how many units different amounts buy, read How many ZESCO units for your money.

Sources

• ZESCO - Prepaid Electricity Tariffs

• ERB - Approved Tariff Schedule