How Best Broadband Deals 2026 Calculates the Effective Monthly Cost of a Broadband Deal

Best Broadband Deals 2026 calculates the effective monthly cost by adding up all the monthly costs, price rises and any discounts across the whole contract, then dividing that total by the contract length. It applies to the deals listed on the site, which are typically 24-month contracts, and it exists so you can compare packages fairly instead of judging them by the headline monthly price alone.

The formula in plain terms

The site states the method directly: "Effective monthly cost is calculated by adding up all the monthly costs, price rises and any discounts and dividing it by the contract length."

So the calculation has three inputs and one output:

Output: a single per-month figure that reflects the full term, not just the first few months.

Why the headline price is not enough

Advertised prices on the site can change during the minimum term. The listing for Sky Full Fibre Gigafast, for example, carries the note "Price may change again during minimum term," and its £100 gift card only reduces the real cost if you actually claim it — the site notes you get instructions up to 120 days after purchase and then have 90 days to claim.

That is exactly the gap the effective monthly cost is designed to close. A deal that looks cheap in month one can cost more once a mid-contract rise lands, and a deal with a higher headline price can come out cheaper once a discount is counted.

Worked example: Virgin Media Gig1 Fibre Broadband

The Virgin Media Gig1 listing shows a staged price rather than a flat one:

• £23.99 per month until 31 March 2027
• £27.99 per month until 31 March 2028
• £31.99 per month from 1 April 2028

The listing also states "No price rise until 2027," a 24-month contract, zero upfront cost, and an average speed of 1.1Gb. Its displayed effective monthly cost is £23.99.

The important point for comparison is that the £23.99 figure is the output of the method above, not simply the first-stage price. When you compare this deal against another, you are comparing full-term averages on the same basis.

What this means when you compare deals

• Compare like with like. Two deals with the same headline price can have different effective costs if one has a scheduled rise and the other does not.
• Check the discount conditions. A gift card only lowers your effective cost if you claim it within the stated window.
• Read the price-change notes. Phrases such as "price may change again during minimum term" signal that the effective cost, not the opening price, is the number to trust.
• Use the site's own figure. Each listing publishes its effective monthly cost, so you do not need to rebuild the sum yourself — but understanding how it was built tells you which deals are genuinely cheaper over 24 months.

Where to go next

The site's comparison flow starts by asking for your postcode to show what is available in your area, and it also publishes a guide on broadband price rises if you want to understand how mid-contract increases work before choosing.