About the Sales Funnel Calculator
This sales funnel calculator models how traffic turns into revenue across four stages: visitors, leads, sales opportunities and customers. In forward mode, enter your monthly visitors and the conversion rate at each step to see how many leads, opportunities and customers you can expect, the revenue they bring and your cost per customer. In reverse mode, enter a revenue goal and it works backward to the customers, opportunities, leads and visitors you need.
It is designed for founders, marketers and sales leaders building a plan or a budget — whether that is a B2B pipeline (visitor → lead → qualified opportunity → closed deal) or an e-commerce or course funnel (visitor → email subscriber → trial or cart → buyer). The stage table shows where most prospects drop out, so you can see which conversion rate is worth improving first.
The model assumes conversion rates stay constant as volume changes and that every stage completes within the same period. Real funnels have time lags and diminishing returns as you buy more traffic, so use your own historical rates and revisit the plan as results come in.
With the default inputs, the customers is 30. Change any value above to recalculate instantly.
How to use the sales funnel calculator
- 1Choose forward mode to project results from traffic, or reverse mode to plan from a revenue goal.
- 2Enter monthly visitors or your revenue goal.
- 3Enter the conversion rate for each stage from your analytics or CRM.
- 4Enter average revenue per customer and, optionally, monthly spend.
- 5Review customers, revenue and the stage table to find the weakest step.
Formula and method
Each stage multiplies the previous one by its conversion rate: leads = visitors × visitor-to-lead rate (r₁), opportunities = leads × lead-to-opportunity rate (r₂) and customers = opportunities × close rate (r₃). Revenue is customers × average revenue per customer, and the overall conversion rate is the product r₁ × r₂ × r₃.
Reverse mode divides instead: customers needed = revenue goal ÷ average revenue per customer, and each earlier stage = the next stage ÷ its conversion rate. Every reverse stage is rounded up to a whole number, because you cannot close part of a deal. Cost per lead and CAC divide your monthly spend by leads and customers.
- r₁
- Visitor → lead conversion rate
- r₂
- Lead → opportunity conversion rate
- r₃
- Opportunity → customer (close) rate
- ARPC
- Average revenue per customer
Worked examples
20,000 visitors through a B2B funnel
3% of 20,000 visitors become 600 leads; 25% of those become 150 opportunities; a 20% close rate yields 30 customers worth $15,000. With $5,000 of spend, each customer costs $166.67 and the return on spend is 200%.
Reverse: what does $50,000 a month take?
At $500 per customer you need 100 customers. A 20% close rate needs 500 opportunities, a 25% qualification rate needs 2,000 leads, and a 3% lead rate needs 66,667 visitors a month.
E-commerce funnel with higher rates
50,000 visitors × 10% × 40% × 30% = 600 buyers, a 1.2% overall conversion rate. At $80 each that is $48,000 in revenue, a $33.33 cost per customer and a 140% return on $20,000 spend.
Frequently asked questions
What is a sales funnel?+
A sales funnel is the sequence of stages a prospect passes through before buying — typically awareness (visitors), interest (leads), consideration (qualified opportunities) and purchase (customers). Fewer people remain at each stage, which gives it the funnel shape.
How do I calculate how many leads I need?+
Divide your revenue goal by average deal size to get customers needed, divide that by your close rate to get opportunities, and divide opportunities by your lead-to-opportunity rate. Reverse mode in this calculator does the whole chain for you.
What are typical funnel conversion rates?+
They vary too much by industry, channel, price point and how each stage is defined to give a reliable benchmark — a free-trial signup and a demo request are very different “leads”. Pull the last 3–6 months of stage counts from your analytics and CRM, divide each stage by the one before it, and use those rates here.
Which funnel stage should I improve first?+
Because stages multiply, a 10% relative gain at any stage lifts customers by 10%. Focus on the stage that is cheapest to improve — often the weakest rate or the one with the clearest fix, such as faster lead follow-up.
What is the difference between CPL and CAC?+
Cost per lead (CPL) is spend divided by leads generated; customer acquisition cost (CAC) is spend divided by new customers won. CAC is always higher than CPL unless every lead buys, and it should be compared with customer lifetime value.