Lost Sales Calculator

Track missed demand, revenue loss, profit leakage, recovery. Test stockout days, sessions, pricing, and margins. Reduce future shortages using sharper inventory decisions every week.

Calculator Inputs

Use traffic, conversion, pricing, stockout, margin, and paid acquisition assumptions to estimate missed sales and financial exposure.

Average daily site visits or sessions.
Percentage of sessions that become orders.
Average revenue earned per order.
Margin percentage retained before fixed overhead.
Duration items remain unavailable for purchase.
Share of demand influenced by unavailable products.
Customers who return later and still buy.
Portion of sessions coming from paid channels.
Average advertising cost per paid session.
Reset

Example Data Table

These sample scenarios show how stronger traffic, longer stockouts, and lower recovery rates increase missed revenue and profit leakage.

Scenario Daily Sessions Conv. % AOV Margin % Stockout Days Affected % Recovery % Estimated Net Lost Revenue
Small Catalog Gap 1200 2.1 62 35 3 25 30 1,171.80
Seasonal Bestseller Outage 2500 2.8 78 42 6 55 18 17,580.60
Major Promotion Failure 5200 3.4 91 46 5 70 10 50,635.20

Formula Used

Affected Sessions Per Day
Daily Sessions × Affected Demand Share
Affected Orders Per Day
Affected Sessions Per Day × Conversion Rate
Gross Lost Orders
Affected Orders Per Day × Stockout Days
Recovered Orders
Gross Lost Orders × Recovery Rate
Net Lost Orders
Gross Lost Orders − Recovered Orders
Net Lost Revenue
Net Lost Orders × Average Order Value
Net Lost Gross Profit
Net Lost Revenue × Gross Margin
Wasted Ad Spend
Daily Sessions × Stockout Days × Affected Share × Paid Traffic Share × Cost Per Session
Total Opportunity Impact
Net Lost Gross Profit + Wasted Ad Spend

This model estimates financial exposure from inventory unavailability. It assumes conversion, pricing, and traffic quality stay stable during the stockout period.

How to Use This Calculator

  1. Enter your average daily sessions.
  2. Provide the normal site conversion rate.
  3. Add the average order value and gross margin.
  4. Enter how many days the product or group stays unavailable.
  5. Estimate the share of demand affected by the outage.
  6. Set a recovery rate for customers who return later.
  7. Enter paid traffic share and cost per session for ad waste.
  8. Click calculate to view lost revenue, profit, and opportunity cost.

Frequently Asked Questions

1. What does this lost sales calculator measure?

It estimates how much revenue, gross profit, and advertising efficiency you may lose when key products are unavailable during active demand periods.

2. Why is affected demand share important?

Not every stockout harms the whole catalog. This input isolates the share of demand tied to unavailable items, making the estimate more realistic.

3. What is the recovery rate?

Recovery rate represents shoppers who delay the purchase and return later after stock is restored, reducing permanent revenue loss.

4. Does this calculator estimate profit or only revenue?

It estimates both. Net lost revenue reflects missed sales value, while net lost gross profit applies your gross margin to that revenue.

5. Why include paid traffic share and cost per session?

Those fields estimate advertising spend wasted on shoppers who arrived through paid campaigns but could not buy the unavailable products.

6. Can I use this for a single SKU or a category?

Yes. Use a low affected share for a single item and a higher affected share for broader category outages or bestseller shortages.

7. Is annualized revenue risk an exact forecast?

No. It is a directional estimate based on current assumptions. Seasonal swings, competitor actions, and demand shifts can change actual outcomes.

8. How can this analysis improve operations?

It helps prioritize replenishment, safety stock, paid media controls, supplier escalation, and forecast planning for the most valuable products.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.