Payback calculator
Type what one new client leaves you. The ruler reads off how many clients the work has to bring in before it has paid for itself, at my published prices. For an internal tool, it reads months of hours saved instead.
I can’t promise you clients. I can do the division.
Whole euros. Use the first year’s gross profit, not the revenue. My scale runs from €500 to €50,000.
A website from €16,000 pays for itself with so many clients that leave you your number each.
- Formula
- clients = price ÷ what one new client leaves you
- Your sum
- Waiting for your number
- Source
- Your number, not mine
From your trafficOptional. What lift would the new site need? Your numbers only.
For reference, not filled in for you: B2B SaaS 1.1%, IT and managed services 1.5%, financial services 1.9%, manufacturing 2.2% (First Page Sage, client data 2022 to 2025). One landing page: a median of 6.6%, SaaS 3.8% (Unbounce, 2024).
For reference: roughly 2% to 4% in B2B SaaS. That range is derived, not published: I multiplied the funnel stages First Page Sage reports (3.7% for the SEO channel, 2.2% for small-business targets).
What one new client leaves you comes from the field above, which is still empty.
Fill in the three numbers, and what one new client leaves you. The table fills in as you type.
| Scope | Clients | Lift, 12 months | 24 months |
|---|---|---|---|
| Landing page €8k | · | · | · |
| Migration €12k | · | · | · |
| Brand identity €14k | · | · | · |
| Website €16k | · | · | · |
| Product or MVP €24k | · | · | · |
| Brand + website €28k | · | · | · |
| App €32k | · | · | · |
Lift = clients needed ÷ (clients a month now × months). The 24-month column is there because sites last about that long: “The average website lifespan for top marketing brands is 2 years and 1 month” (Orbit Media).
It starts at zero. Nothing is assumed for you.
What others measured. None of it is used in the sum.
“A 31% improvement in LCP led to 8% more sales.”
Vodafone, an A/B test on one landing page. web.dev“A 21.6% improvement in the number of users that progressed to the Form Submission Page”, per 0.1 s of mobile speed.
Lead-generation sites in a study of 37 brands, 2019. web.dev
Read it with care. The benchmarks are vendors’ own datasets, not your market. A redesign can lower conversion as well as raise it. B2B revenue lands months after the lead. The sum ignores whatever else changes in the same period. I can’t promise clients. I can do the division.
How this is calculated
The sum
Clients = price ÷ what one new client leaves you, rounded up, because nobody wins half a client. That is all of it. The working is printed under the answer so you can check it. An internal tool brings no clients, so for one the sum is months = price ÷ what the hours it saves are worth a month, rounded up the same way.
The prices
Each mark on the right-hand scale is a starting price from my price list. Prices excl. VAT. Your own project gets a fixed price in writing before any work starts, so the real number may sit above the mark, never above the quote.
What a client leaves you
Use what a new client leaves you in the first year after your own costs: gross profit, not revenue. If you sell subscriptions, take twelve months of margin. If you only know revenue, the answer will flatter the work.
The drawing
It is a nomograph: three scales set so that a straight line does the division. The outer two are logarithmic, your number on the left and my prices on the right, drawn upside down. A line from one to the other crosses the middle scale exactly at price ÷ your number. Engineers used these before calculators. It is here because you can see the answer move.
From your traffic
Clients a month now = visitors × the share who become a lead × the share of leads who become a client. Lift needed = clients needed ÷ (clients a month now × months). The lift slider uses the same rounded-up count of clients, so its months and the table agree. The benchmarks beside the fields are there to compare with. They are never filled in for you and never used in the sum.
What it leaves out
Everything else that changes while a new site is live: your ads, your prices, the season, a competitor. A redesign can lower conversion as well as raise it. Nothing you type is saved or sent anywhere.