Practical Calculator Guide

Electricity cost calculators and guides for checking everyday usage assumptions.

Electricity cost calculator

kWh to Cost Calculator

Price known kWh for the period it represents, whether it came from a meter, a cycle, a bill, or another calculator.

Enter the kWh amount you want to convert into cost.

Electricity rate

Copy the rate number, then choose how it is written below.

Choose a 0.20-style currency amount or a 20-style cents/pence value.

Only choose one day when the entered kWh is a single day's use. Do not scale a cycle, bill, or measured period to 30 days automatically.

Not sure what rate to enter? Read how to find your electricity rate per kWh.

Before converting

Match the kWh to one period

Choose the period once in the form and keep it with the result. This prevents a cycle, meter interval, or bill from being treated as one day by mistake.

  • One day: use only for one day's energy; this is the only choice that enables the optional 30-day estimate.
  • One cycle, session, or measured period: price that bounded use first, then scale only if it repeats.
  • Billing period, month, or annual total: price the entered kWh as that whole period, not as one appliance day.

Define a meter interval with the smart-plug measurement guide. Separate kWh from other statement lines with the bill-input guide.

Illustrative input

Example: pricing one labeled meter reading

In this illustrative example, a plug-in monitor records 1.70 kWh across two selected evenings. Enter 1.70 as the kWh amount and choose the measured-period option. At a sample rate of 0.17 per kWh, the estimated usage cost is 0.29 after final rounding.

This is different from starting with watts and hours because the measured kWh is already the input. For the measurement workflow, use the smart-plug measurement guide. Keep the rate source beside the result if you later compare it with a statement.

Formula

kWh to cost formula

cost = kWh x electricity rate per kWh

For example, 12.5 kWh at a sample rate of 0.20 per kWh gives an estimated usage cost of 2.50 in the currency used for that rate.

Limits

What the entered rate may not include

The result reflects whatever the rate you entered already includes. Tiered pricing, time-of-use changes, and a rate source that does not cover every bill line can make a statement total different from this result. Use the bill-difference guide to examine that comparison without changing the selected kWh period.

FAQ

Frequently asked questions

When should I use this instead of an appliance cost calculator?

Start here when you already know kWh. Use the appliance cost calculator when you need to start from watts and hours per day.

What if my electricity plan has multiple rates?

Use the rate that applies to the kWh you are estimating, or run separate estimates for peak and off-peak rates.