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Conversion rate calculator

The share of your visitors who buy, sign up or get in touch, and what it would take to do better.

Conversion rate

For the period you choose: unique visitors or sessions, whichever your analytics tool counts.

Orders, sign-ups, enquiries and so on, over the same period and the same pages.

Order value and target (optional)

Gives the average order value and the revenue per visitor. With or without VAT, as long as you stick to one.

£

How many conversions the same traffic would need to reach it.

%
Compare with another period (optional)

The previous period, or the other version of a page you are testing.

Conversion rate

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Enter the number of visitors and conversions to see the rate.

Visitors (or sessions)
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Conversions
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Recent calculations

Nothing yet: copy, export or save a calculation to find it here.

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How it works

Enter the number of visitors (or sessions) your website had over a period, and the number of conversions over the same period: orders, sign-ups, enquiries. You get your conversion rate to two decimal places, with every step of the working. If you like, add your revenue and a target rate to see your average order value and how many more conversions you would need, or another period’s figures to measure the change.

Decide what you count

A conversion is the action you want a visitor to take: an order in an online shop, a newsletter sign-up, a quote request. Count it over the same pages and the same period as the visitors. In a physical shop, the same ratio is worked out from buyers and footfall.

Visitors or sessions

Divide by visitors to see what share of people converted, or by sessions to see what share of visits ended in a conversion. Google Analytics 4 reports both: the session key event rate is sessions in which a key event happened ÷ all sessions, and the user key event rate is users who performed a key event ÷ all users. Stick to one denominator from one period to the next, or the rates will not compare.

Count real visitors only

The GOV.UK Service Manual, which measures the completion rate of government online services in the same way, asks services to exclude internal users, test users and web robots. Think too about the visitors your tool cannot see: if your orders come from your back office but your visitors come from a tool that leaves out people who object to its cookies, the rate will be overstated.

Targets and comparisons

With a target rate, the calculator gives the conversions the same traffic would need, rounded up to a whole conversion, and, if you entered revenue, what they would bring in at your current average order value. With another period, it gives the difference in percentage points and the relative change, which say different things: from 2% to 2.5%, the rate gains 0.5 percentage points, a rise of 25%.

Rounding

Rates are rounded to the nearest hundredth of a percentage point and money to the nearest penny, with halves rounded up. The extra revenue starts from the average order value shown. The difference and the relative change (to one decimal place) start from the unrounded rates, because two rates that both show as 0.01% can hide a doubling; the working then shows the fractions, so you can still check every line by hand.

Conversion rate = conversions ÷ visitors × 100.

Visitors per conversion = visitors ÷ conversions.

Average order value = revenue ÷ conversions; revenue per visitor = revenue ÷ visitors.

Conversions needed = visitors × target rate ÷ 100, rounded up to a whole number.

Difference (percentage points) = rate − rate in the other period; relative change = difference ÷ rate in the other period × 100.

Example: 200 orders from 8,000 sessions

Last month an online shop had 8,000 sessions and took 200 orders worth £12,400.00. Its conversion rate is 200 ÷ 8,000 × 100 = 2.5%, one order for every 40 sessions. The average order value is £62.00 and each session brings in £1.55. To reach 3% from the same traffic it would need 240 orders, 40 more, worth £2,480.00 at the current average order value. The month before, 150 orders from 7,500 sessions gave 2%, so the rate has gained 0.5 percentage points, a rise of 25%.

Frequently asked questions

How do I calculate a conversion rate?

Divide the conversions by the visitors for the same period, then multiply by 100. With 45 sales from 1,800 visitors: 45 ÷ 1,800 × 100 = 2.5%. In other words, one visitor in 40 bought something.

Should I divide by visitors or by sessions?

Either works, but do not mix them. Per visitor, counting each visitor who converts once, the rate tells you what share of people converted; per session, what share of visits did, and it falls when customers come back several times before buying. Google Analytics 4 offers both, as the user key event rate and the session key event rate.

My rate went from 2% to 2.5%: is that a rise of 0.5% or 25%?

Both figures are right if you name them properly. The rate gained 0.5 percentage points (2.5 − 2); measured against where it started, it rose by 25% (0.5 ÷ 2 × 100). Calling it ‘a rise of 0.5%’ is a common mistake: that would mean going from 2% to 2.01%.

Why does my analytics tool show fewer visitors than my server logs?

Because it filters out bots and often internal traffic, and because it does not always see everyone. Since 5 February 2026, UK law has let a website set analytics cookies without asking for consent first, provided they are used only to collect statistics on how the site is used in order to improve it, the data is not shared except with those helping to improve it, and visitors are told clearly and given a simple, free way to object (the Privacy and Electronic Communications Regulations 2003, Schedule A1, paragraph 5). Visitors who object, or who block cookies, are not counted. If your orders come from your back office, which sees every sale, divide them by visitors measured on the same basis, or the rate will be too high.

What is a good conversion rate?

No official body publishes a benchmark, and the averages quoted online mix very different sectors, devices and traffic sources. The most reliable yardstick is your own history: compare one period with the previous one, or two versions of the same page, with the same denominator and the same conversions.

Can a conversion rate be above 100%?

Only if you count something other than visits that convert: every order when some visitors place several, or orders from the whole site against visits to a few pages. The calculator still works it out, with a warning. Analytics tools avoid this by counting the sessions in which at least one key event happened, as Google Analytics 4 does.

Sources

  1. GOV.UK Service Manual: Measuring completion rate (19 February 2021)
  2. Google Analytics Help: Analytics dimensions and metrics, session key event rate and user key event rate (retrieved 11 November 2026) (11 November 2026)
  3. legislation.gov.uk: Privacy and Electronic Communications (EC Directive) Regulations 2003, Schedule A1, paragraph 5 (statistical purposes), in force from 5 February 2026 (5 February 2026)

This calculator gives general information, not legal, tax, financial or accounting advice. The result depends on the visitors and conversions you count: check that they cover the same period and the same pages.

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