Clear CalculatorsStart with the simple pound difference
Subtract the old price from the new price. If a monthly bill rises from GBP 45 to GBP 52, the change is GBP 7 a month. That is often the clearest figure for a household budget because it shows the additional cash needed in the next payment period.
The Price Increase Calculator also turns the change into a percentage and estimates its yearly effect for weekly or monthly prices.
Why the percentage can tell a different story
Percentage change puts the increase in context. A GBP 7 rise on a GBP 45 bill is a much larger percentage than the same GBP 7 rise on a GBP 200 bill. Both figures are worth seeing: the pound amount helps with budgeting, while the percentage helps compare changes across different services.
When the old price is zero, a percentage is not meaningful. In that case, describe the new charge in pounds and check whether it is a genuinely new service or an old discount ending.
Compare like with like
Do not compare an annual price with a monthly price without converting one of them first. Divide an annual charge by 12 to create a monthly average, or multiply a monthly charge by 12 to compare two annual totals. Weekly prices use 52 payments in a broad yearly estimate.
One-off setup fees, delivery fees and late-payment charges are different from a recurring price. Keep them separate so they do not make a regular increase look larger or smaller than it is.
Read the reason for the change
A provider notice may mention an increase, but the actual bill can also change because of usage, tax, a discount ending, a different payment method, a new tariff or a separate fee. The calculator compares the two numbers you enter. It does not decide whether the supplier's reason is correct or whether another product is suitable.
For electricity, compare unit rates and standing charges rather than relying only on one monthly bill. For several subscriptions, add them in the Subscription Cost Calculator to see their combined effect.
A quick checking routine
- Write down the old and new price and their start dates.
- Make the periods match: weekly, monthly or annual.
- Check whether a discount, usage level or fee changed too.
- Calculate the pound and percentage difference.
- Use the annual view only as a projection, not a guaranteed bill.
This gives you a tidy record if you need to question a bill or simply adjust a budget.
Useful tools
Estimate only. A yearly figure assumes the same price applies for a full year. Check notices, bills, terms and supplier information for the actual start date, discounts and fees.