Calculator inputs
Enter current performance values, projected speed improvement, and commercial assumptions. The result appears above this form after submission.
Formula used
The calculator blends direct conversion effects, bounce-rate changes, and organic traffic movement to estimate business impact from page speed changes.
1. Speed change
Seconds Improvement = Current Load Time − Projected Load Time
2. Projected bounce rate
Projected Bounce Rate = Current Bounce Rate × (1 − Seconds Improvement × Bounce Change per Second / 100)
3. Engagement multiplier
Engagement Multiplier = (100 − Projected Bounce Rate) ÷ (100 − Current Bounce Rate)
4. Projected conversion rate
Projected Conversion Rate = Current Conversion Rate × (1 + Seconds Improvement × Conversion Change per Second / 100) × Engagement Multiplier
5. Projected sessions
Projected Sessions = Non-Organic Sessions + Organic Sessions × (1 + Seconds Improvement × Organic Traffic Lift per Second / 100)
6. Revenue and profit
Revenue = Sessions × Conversion Rate × Average Order Value
Gross Profit = Revenue × Gross Margin
7. Payback period
Payback Months = Optimization Cost ÷ Incremental Gross Profit
How to use this calculator
- Enter your current monthly sessions, load time, conversion rate, and bounce rate.
- Add the load time you expect after technical improvements.
- Set sensitivity assumptions for bounce, conversion, and organic traffic movement.
- Enter commercial values like order value, gross margin, ad spend, and project cost.
- Submit the form to see forecasted revenue, profit, payback, and scenario curves.
- Download the result as CSV or PDF for planning, meetings, or campaign approvals.
Example data table
This sample scenario shows how the calculator behaves with realistic marketing assumptions.
| Metric | Example Value |
|---|---|
| Monthly Sessions | 120,000 |
| Current Load Time | 4.20 seconds |
| Projected Load Time | 2.60 seconds |
| Current Conversion Rate | 2.80% |
| Average Order Value | $95.00 |
| Current Bounce Rate | 42.00% |
| SEO Traffic Share | 48.00% |
| Projected Revenue | $371,607.88 |
| Incremental Revenue | $52,407.88 |
| Projected Conversions | 3,911.66 |
| Incremental Gross Profit | $27,252.10 |
| Payback Months | 0.92 |
FAQs
1. What does this calculator estimate?
It estimates how page speed changes may influence bounce rate, conversion rate, total sessions, revenue, gross profit, MER, CPA, and payback period. It helps marketers turn technical improvements into financial forecasts.
2. Why are bounce and conversion sensitivities separate?
Speed can affect behavior in more than one way. Some gains come from fewer early exits, while others come from stronger buying or lead intent among visitors who stay. Separate sensitivity inputs let you model both effects.
3. How should I choose per-second assumption values?
Start with past experiments, analytics patterns, or public benchmarks from similar pages. Use cautious values first, then compare moderate and aggressive scenarios. A range-based approach is more reliable than one optimistic forecast.
4. Can I test a slower page too?
Yes. Enter a projected load time that is higher than your current load time. The model will treat that as a slowdown and show the likely downside in conversions, revenue, efficiency, and payback.
5. Why is SEO traffic share included?
Improved speed can influence organic visibility and user satisfaction, which may lift search-driven sessions. This input limits that effect to the share of traffic you believe is realistically exposed to search performance changes.
6. What happens if I have no ad spend?
The calculator still works for revenue and profit forecasting. MER and CPA become unavailable because they need paid media spend to calculate. This is helpful for teams focused mainly on organic or lifecycle traffic.
7. Is gross margin required?
Gross margin is needed if you want contribution profit and payback estimates. Without it, revenue still shows the top-line opportunity, but you lose a better view of business value after direct delivery costs.
8. Can this work for lead generation instead of ecommerce?
Yes. Replace average order value with average revenue per lead, pipeline value per qualified lead, or estimated lead contribution. The calculator then behaves like a speed-to-demand forecast rather than a retail sales model.