Website redesign ROI calculator
See what a lift in conversion rate is worth per month, how fast a website redesign pays for itself and the 12-month return, on profit, not just revenue. Works for ecommerce and lead generation sites.
- Free, no signup
- Runs in your browser
- Nothing is uploaded
Your site today
Use last month's analytics, or an honest average.
What you keep after product or delivery costs. Set 100% to calculate on revenue, which flatters the result.
After the redesign
The lift is relative: 2.0% → 2.3% is a 15% lift.
Hosting, plugins, tools
What the lift is worth
Per month, from 200 orders today.
Extra orders / month
30
Extra revenue / month
$2,400
$1,170 after margin and running costs
Payback (days)
52
Until the redesign has paid for itself
12-month ROI
602%
$12,041 net after the redesign cost
Cumulative net gain, first 12 months
Below the line, the redesign has not paid for itself yet.
| Month 1 | -$829 |
|---|---|
| Month 2 | $341 |
| Month 3 | $1,511 |
| Month 4 | $2,681 |
| Month 5 | $3,851 |
| Month 6 | $5,021 |
| Month 7 | $6,191 |
| Month 8 | $7,361 |
| Month 9 | $8,531 |
| Month 10 | $9,701 |
| Month 11 | $10,871 |
| Month 12 | $12,041 |
Scenarios side by side
Same inputs, three different lifts.
| Scenario | Extra revenue / mo | Payback | 12-month ROI |
|---|---|---|---|
| Conservative +5% | $800 | 5.4 months | 122% |
| Expected +15% | $2,400 | 52 days | 602% |
| Optimistic +30% | $4,800 | 26 days | 1,323% |
Want proof rather than a projection? Run the new design against the old one and check the result with the A/B test significance calculator.
An estimate, not a promise. A redesign can lift conversion, leave it flat or, done badly, lower it. The defaults are editable assumptions; plug in your own analytics and treat the conservative row as the planning number.
How it works
How to use the website redesign roi calculator
- 01
Pick your model
Choose ecommerce (orders and order value) or lead generation (enquiries, close rate and deal value).
- 02
Enter today's numbers
Monthly visitors, conversion rate, order or deal value and the margin you keep. Last month's analytics is a good source.
- 03
Choose a realistic lift
Start from the conservative, expected or optimistic scenario, then fine-tune the lift, traffic change and costs.
- 04
Read the payback
See extra revenue per month, the payback period, 12-month ROI and when the redesign moves into profit. Share the link.
How website redesign ROI is calculated
A redesign earns its keep by converting more of the visitors you already have. The maths is simple once you separate the steps:
- Extra conversions = visitors × (1 + traffic change) × conversion rate × (1 + lift) − visitors × conversion rate
- Value per conversion = average order value, or close rate × deal value for leads
- Net monthly gain = extra conversions × value × gross margin − extra running costs
- Payback = redesign cost ÷ net monthly gain
- 12-month ROI = (12 × net monthly gain − redesign cost) ÷ redesign cost
A worked example with the defaults: 10,000 visitors a month at a 2% conversion rate is 200 orders. A 15% lift takes the rate to 2.3%, or 230 orders, so 30 extra orders at $80 is $2,400 of extra revenue. At a 50% margin you keep $1,200; minus $30 of extra running costs, $1,170 a month. A $1,999 redesign pays back in about 52 days and returns roughly 600% over the first year.
Relative lift vs percentage points
This trips up a lot of business cases. A conversion rate going from 2.0% to 2.3% is a 0.3 percentage point increase but a 15% relativelift. The slider uses relative lift, the way A/B testing tools report results. Claiming a “15% increase” when you mean 2% to 17% is the kind of number that gets a whole proposal ignored.
Valuing leads on a lead generation site
For a lead generation site, a conversion is an enquiry, not a sale. Value it at close rate × deal value: if one in five enquiries becomes a $3,000 customer, each enquiry is worth $600 before margin. Take both numbers from your CRM rather than memory. Watch one trap: a redesign that brings in more, lower-quality enquiries can raise the conversion rate while lowering the close rate. If that is a risk, nudge the close rate down when you model the lift.
What lift is realistic?
Nobody can promise a number, and you should be wary of anyone who does. What a redesign can achieve depends on what is wrong today. Use the scenarios as planning ranges, not predictions:
| Scenario | Relative lift | When it is plausible |
|---|---|---|
| Conservative | 5% | The site works; the redesign tidies messaging, speed and mobile layout |
| Expected | 15% | Clear problems are fixed: a vague offer, weak trust signals, a slow or clumsy checkout |
| Optimistic | 30% | The current site is genuinely broken on mobile, very slow, or hides the price and the next step |
Big headline lifts usually come from fixing something broken, not from a prettier hero. Make the business case on the conservative row, then measure. The A/B test calculator tells you when a difference is real and not noise.
Common mistakes in redesign business cases
- ROI on revenue. Without margin, a store with 40% margins overstates its monthly gain by 2.5 times.
- Assuming an instant lift. New sites often settle in over a few weeks as you fix issues real visitors find. Payback in reality is a little slower than the straight line.
- Ignoring seasonality. Compare like-for-like periods, not December against February.
- Forgetting SEO. Changing URLs without 301 redirects can lose search traffic that took years to build. Use the traffic slider to model a dip if you are migrating platforms.
- Leaving out running costs. A platform with higher monthly fees eats into the gain every month.
What actually moves conversion
In my experience the gains come from a handful of unglamorous things: pages that load fast on a mid-range phone (see Core Web Vitals), an offer a visitor understands in five seconds, visible proof, a price or a next step they do not have to hunt for, and forms with as few fields as possible. More on the metric itself in the conversion rate glossary entry.
The default redesign cost of $1,999 is my fixed price for a complete custom website, agreed before work starts. If your numbers say a redesign pays back, my website design service is built around conversion first, and you can browse high-converting SaaS landing pages for ideas.
Common questions
Website redesign ROI calculator: FAQ
Work out the extra conversions the redesign brings (visitors × conversion rate after, minus visitors × conversion rate before), multiply by the value of a conversion and your gross margin, then subtract any extra running costs. ROI over 12 months is (12 × that monthly gain − redesign cost) ÷ redesign cost.
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