How to build an ROI calculator for B2B lead generation
An ROI calculator lets a visitor type in a few numbers about their own business and see, instantly, what switching to your product would be worth to them. It is one of the highest -converting pieces of content a B2B marketing site can have, because the visitor does the selling themselves.
1. Pick one number your buyer already cares about
Good calculators answer a single question: "How much time/money would I save?" or "How much more would I make?". Avoid calculators with more than 3-4 inputs — every extra field loses visitors. Typical inputs: team size, hours spent per week on a task, average deal size, or current monthly spend on a competitor.
2. Write the formula before you build anything
Keep the formula honest and simple enough that a prospect can sanity-check it in their
head. For example: monthly_savings = hours_per_week * 4.33 * hourly_rate * automation_rate.
If the result looks implausible, visitors stop trusting the rest of your site.
3. Put the result above the fold, with a clear next step
Show the number large, then a single call to action: "Get this result emailed to you" (capturing the lead) or "Talk to sales". Don't bury the result below more marketing copy.
4. Build it without a developer
In Calcly, you add your input fields and formula in a form, and get an embed snippet for your existing landing page — no JavaScript to write. Every submission (with the inputs and result) lands in your dashboard so your sales team can follow up with context.