Electricity Bill Formula Explained, With Examples
Every electricity bill result comes from one formula. Once you understand what goes into it, you can sanity-check any figure you are given, whether by an employer, a bank, a teacher or another website.
The formula
Cost = kWh × tariff.
What each input means
- Monthly usage (kWh): the value you enter in the calculator.
- Tariff (cents per kWh, incl. GST): the value you enter in the calculator.
Example
For example, with these inputs:
- Monthly usage (kWh): 350
- Tariff (cents per kWh, incl. GST): 30
the calculator returns:
- Monthly electricity cost: S$105.00
- Annual cost: S$1,260.00
How the result changes
The table keeps the other inputs at their example values and changes monthly usage (kwh).
| Monthly usage (kWh) | Monthly electricity cost | Annual cost |
|---|---|---|
| 350 | S$105.00 | S$1,260.00 |
| 175 | S$52.50 | S$630.00 |
| 262 | S$78.60 | S$943.20 |
| 438 | S$131.40 | S$1,576.80 |
| 525 | S$157.50 | S$1,890.00 |
Why it matters
Interest rates, instalments and returns compound over years, so a small difference in rate or tenure turns into thousands of dollars. Working the numbers out yourself makes it easier to compare bank offers, avoid expensive debt and plan savings goals.
Cars in Singapore carry costs found almost nowhere else, including the Certificate of Entitlement and the Additional Registration Fee. Loans are capped at 60% or 70% of the price depending on the car's Open Market Value, and the maximum tenure is seven years.
Inflation erodes buying power, so a savings goal set in today's dollars needs to be adjusted upwards for the years it will take to reach it. Singapore's core inflation has varied widely over the past decade, so it is worth testing a range of rates.
An emergency fund of three to six months of essential expenses protects you from having to borrow at high rates when something unexpected happens. Once that buffer is in place, extra savings can go towards longer-term goals and investments.
Related calculations
- Simple Interest Calculator: Calculates simple (non-compounding) interest.
- Savings Goal Calculator: Finds how much to set aside each month to hit a target.
- Future Value Calculator: Projects savings with regular monthly contributions.
- Present Value Calculator: Finds what a future sum is worth today.
Use the Electricity Bill Calculator to plug in your own numbers.
Run your own numbers: Electricity Bill Calculator