Fictional worked example

Price extra use across an electricity tier

A household is close to its 300 kWh block limit and wants to price 30 kWh of additional use before hosting visitors.

Open Calculator

Inputs and calculation

Before visitors
Tool inputValue
CurrencyUSD
UtilityElectricity (kWh)
Metered usage290
Tariff typeTiered rate
Cumulative upper limit, price per unit300, 0.16
*, 0.30
Service fee (USD)10
Tax on usage plus service fee (%)0

290 × 0.16 + 10 = 56.40.

Tool result · USD 56.40

After 30 extra kWh
Tool inputValue
CurrencyUSD
UtilityElectricity (kWh)
Metered usage320
Tariff typeTiered rate
Cumulative upper limit, price per unit300, 0.16
*, 0.30
Service fee (USD)10
Tax on usage plus service fee (%)0

300 × 0.16 + 20 × 0.30 + 10 = 64.00.

Tool result · USD 64.00

What the comparison shows

The first 10 extra kWh cost 1.60 and the remaining 20 cost 6.00. Charging all 30 at the top rate would overstate the difference.

Assumptions and limits

This is an increasing block tariff. Earlier units retain their original rate when usage crosses the boundary.

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