The Sales Funnel Calculator tracks how prospects move through a multi-stage funnel and quantifies conversion at each step. It calculates stage-to-stage rates, overall lead-to-sale conversion, lost prospects, expected customers, and revenue from an average sale value.
Sales and marketing teams can use it to locate the largest drop-off, compare campaigns, and work backward from a revenue target. Each stage should represent the same cohort and reporting window so the conversion rates describe one consistent funnel.
1. Enter the top-of-funnel count
Use visitors, contacts, or prospects from one defined cohort.
2. Add each stage count
Enter leads, qualified opportunities, proposals or trials, and closed sales.
3. Keep the funnel descending
Later-stage counts should not exceed earlier-stage counts.
4. Enter average sale value
Use the average recognized or expected value per closed sale.
5. Review conversion points
Compare overall conversion with the stage rates to find the largest opportunity for improvement.
The model treats every count as part of the same funnel cohort and does not adjust for sales-cycle timing or repeat purchases.
The main result is the percentage of top-of-funnel prospects that became closed sales.
For long sales cycles, cohort-based tracking is usually more informative than comparing unrelated monthly totals.
Given: 20,000 visitors, 1,800 leads, 540 qualified opportunities, 220 proposals, 70 sales, and $2,400 average value.
Calculation: Overall conversion = 70 ÷ 20,000 × 100 = 0.35%. Lead-to-qualified = 540 ÷ 1,800 × 100 = 30%. Proposal-to-close = 70 ÷ 220 × 100 = 31.82%. Revenue = 70 × $2,400 = $168,000.
Result: The funnel converts 0.35% of visitors into sales and produces an estimated $168,000.
The calculation works for any descending five-stage funnel, even if your internal stage names differ.
A standard funnel represents progression from a larger group to a smaller group. If people can re-enter or skip stages, use cohort rules that avoid double counting.
Choose the unit that matches your funnel design and use it consistently across all stages.
Track a cohort from entry through closing, or allow enough lag before judging the final conversion rate.
Divide the target number of sales by expected conversion at each stage to estimate the required volume upstream.