How to put a euro figure on a conversion problem

Any conversion problem can be priced with one line of arithmetic. Revenue per visitor is conversion rate multiplied by average order value, and the gap between yours and what it should be is the monthly number.

Most founders describe conversion problems in adjectives. Bad. Broken. Underperforming.

Adjectives do not survive a conversation with a co-founder, and they do not help you decide what to fix first. A number does both.

How do you calculate what a conversion problem costs?

Multiply monthly visitors by the gap between your current conversion rate and a realistic target, then multiply by average order value. That gives you the monthly revenue sitting on the table. Revenue per visitor, conversion rate times average order value, is the underlying measure.

Written out, the formula Revslip publishes for its own estimates:

monthly visitors × conversion gap × average order value = monthly recovery

Three inputs, all of which you already have.

Where do the three numbers come from?

Visitors come from your analytics. Average order value comes from your payment processor, total revenue divided by order count. The conversion gap is the only judgement call, and the honest way to set it is against your own best-performing page rather than an industry average.

Conversion figure from DTC Pages, 21 Shopify stores, Q2 2026. Industry ranges from Speed Commerce benchmarks. Two independent sources, and they do not agree precisely, which is the point of the caution further down.

Worked example, start to finish

A store with 4,000 monthly visitors converting at 1.2%, where 2% is realistically reachable, with a €60 average order, is leaving €1,920 a month on the table. That is 32 orders you are already paying to attract and then losing.

Step by step, so you can swap your own numbers in:

1. Visitors. 4,000 a month, from analytics.
2. Current rate. 1.2%, so 48 orders.
3. Target rate. 2%, taken from your own best page, not a blog average. That is 80 orders.
4. The gap. 32 orders a month.
5. Times AOV. 32 × €60 = €1,920 a month, or €23,040 a year.

Now the number does work for you. It ranks fixes, it justifies spend, and it tells you when a €5,000 audit pays back and when it does not.

Not sure what your realistic target is? Revslip prices each finding on your URL using this exact formula.

A conversion problem without a number attached is an opinion. With a number, it is a decision.

Three ways this formula lies to you

The arithmetic is trivial. The judgement is not. The target rate is the input that carries all the uncertainty, and picking it from an industry benchmark rather than your own data is the single most common way the output becomes fiction.

The three failure modes, in order of how often they bite:

1. A borrowed target rate. Benchmarks blend a €12 impulse buy with a €12,000 enterprise deal. Use your own best page instead.
2. Traffic mix drift. Branded and returning visitors convert far better. If your mix shifts, the gap moves without anything on the page changing.
3. Treating the ceiling as a promise. The output is the most you could recover, not what you will. Halve it before you put it in a plan.

Proving the number afterwards

Compare revenue per visitor before and after, not conversion rate alone. A change that lifts conversion while dropping average order value can leave you flat or worse. Match two full weeks against the two before, day for day, and expect a directional read under roughly 400 conversions.

Revenue per visitor is the honest metric because it catches the trade. Lift conversion from 2% to 3% and AOV from €100 to €120 and revenue on the same traffic goes up 80 percent, because the two multiply. Lift one while crushing the other and you have moved nothing.

When this is the wrong tool

Below roughly 500 monthly conversions the formula produces a number with error bars wider than the number itself. At that volume normal month-to-month variance swamps the gap you are trying to measure, and the honest answer is that you cannot price the problem yet.

Long sales cycles break it too. If someone converts ninety days after first visit, this month’s visitors and this month’s orders are different people, and dividing one by the other is meaningless.

Common questions

What target conversion rate should I use?

Your own best-performing landing page, not an industry figure. If one page converts at 3.1% and the rest at 1.2%, then 3.1% is demonstrably achievable with your product, your price and your traffic. That is a far safer target than any published benchmark.

Should I use revenue or profit in the calculation?

Revenue for prioritising, contribution margin for deciding spend. Ranking which fix matters most only needs relative size. Deciding whether to pay for an audit needs margin, because €1,920 of revenue at 30% margin is €576 of actual money.

Does this work for SaaS or lead generation?

Yes, swap average order value for average contract value, or for lead value if you know your close rate and deal size. The structure holds. For lead gen, multiply leads by close rate by deal size to get the equivalent of AOV.

If you want the numbers rather than the arithmetic, run a free audit and every finding arrives already priced.

For context on what a realistic target looks like, the benchmark breakdown covers where the published figures come from and why they disagree. What a CRO audit costs uses this formula to work out the payback threshold, and the conversion leak index lists every signal we price. Revslip’s audit applies it across about 200 checks.