Lost Sales Calculator for Ecommerce

Lost Sales Calculator

Formula Used

Baseline Orders = Visitors × Expected Conversion Rate

Actual Orders = Visitors × Actual Conversion Rate

Conversion Gap Orders = Baseline Orders − Actual Orders

Potential Stockout Orders = Visitors × Affected Traffic Share × Expected Conversion Rate × Unavailable SKU Share

Stockout Lost Orders = Potential Stockout Orders × (1 − Substitution Recovery) × (1 − Backorder Recovery)

Other Lost Orders = Conversion Gap Orders − Stockout Lost Orders

Lost Revenue = Total Lost Orders × Average Order Value

Lost Gross Profit = Lost Revenue × Gross Margin

Wasted Ad Spend = Visitors × Affected Traffic Share × Paid Traffic Share × Cost Per Visit × Unrecovered Stockout Factor

How to Use This Calculator

1. Enter the analysis period in days.
2. Add total visitors for that period.
3. Enter the expected and actual conversion rates.
4. Add average order value and gross margin.
5. Estimate how much traffic saw unavailable products.
6. Enter the share of catalog that was unavailable.
7. Add substitution and backorder recovery rates.
8. Enter paid traffic share and cost per visit.
9. Set a realistic remarketing recovery rate.
10. Submit the form to view lost orders, revenue, profit, and recovery targets.

Example Data Table

Why Lost Sales Tracking Matters in Ecommerce

Lost sales hide inside normal reports. Many stores only track completed orders. That view misses demand that never converted. A strong lost sales model shows the real revenue gap. It connects traffic quality, stock availability, conversion friction, and margin impact in one place.

Measure demand that your store could have captured

Expected conversion rate gives you a benchmark. Actual conversion rate shows what happened. The difference reveals missed orders. That gap becomes more useful when you layer in stockout exposure. Some visitors leave because products are unavailable. Others abandon because delivery, trust, payment, or speed issues create friction.

Separate stockout losses from other conversion problems

This calculator splits lost orders into two groups. First, it estimates stockout losses from affected traffic and unavailable items. Second, it assigns the remaining conversion gap to other issues. That helps ecommerce teams avoid vague decisions. Merchandising, performance marketing, and operations can each see their part of the problem.

Use profit, not only revenue

Revenue loss matters, but margin matters more. A store can recover top line sales and still hurt profitability. Gross margin converts lost revenue into lost gross profit. That number is better for prioritizing fixes. It helps teams compare inventory actions, ad spend changes, and retention campaigns with more discipline.

Turn missed demand into action

Paid traffic share and cost per visit reveal wasted spend. Remarketing recovery shows how much value you may still capture. Break even recovered orders give teams a simple target. If your store improves availability, checkout flow, and follow-up campaigns, you can recover meaningful demand. Better forecasting also reduces future stockout risk. Over time, this improves customer experience, conversion efficiency, and contribution margin across important channels.

FAQs