Your slow load timehas a price tag.
Every second your page makes a visitor wait, a measurable slice of them leave before they convert. This calculator turns that abstract lag into a hard monthly number: the extra orders and revenue a faster site would have banked, based on the conversion drop researchers actually measured.
Your numbers
How long your page takes to load now, in seconds (check PageSpeed Insights or your analytics).
The load time you're aiming for. Aim for 2 seconds or under; 3 seconds is the mobile abandonment cliff.
Sessions landing on the page or flow you're measuring, per month.
The share of those visitors who convert today, at your current speed.
Revenue per conversion: order value, or the value of a lead/signup if that's your goal.
The verdict
Extra revenue / month
$16,800
Extra orders / month
210
Projected conversion rate
3.4%
Conversion lift
14.0%
Annual prize from the speedup
Extra revenue / year
$201,600
Where your load times sit
Past 3 seconds, Google found 53% of mobile visits are abandoned before the page even renders. Get the marker out of the red.
What-if · how fast is fast enough
Extra revenue / month
$16,800
Seconds saved
2
The relationship is linear: every second you shave off lifts conversions by about 7%. Drag the target down and watch the recovered revenue climb, the first seconds out of the danger zone are worth the most. The 7%/sec rule flattens near the ceiling, so the projected rate is capped at 100% (you can't convert more than every visitor).
Sensitivity · target load times
What each speed target is worth
| Target load | Conversion lift | Extra revenue / mo |
|---|---|---|
| 1.0s | +21.0% | $25,200 |
| 1.5s | +17.5% | $21,000 |
| 2.0s | +14.0% | $16,800 |
| 2.5s | +10.5% | $12,600 |
| 3.0s | +7.0% | $8,400 |
All rows assume your current 4.0s. Targets slower than you already are show a dash, there's no speedup to bank. The gain is purely from the seconds you remove.
Breakdown · the recovered money
Monthly vs. annual upside
That $16,800 a month is recurring. A one-time performance sprint keeps paying out every month you stay fast, which is what makes speed one of the highest-ROI fixes you can ship.
Your move
I find the seconds, then I find the money in them.
Cutting load from 4.0s to 2.0s recovers 210 orders/mo → +$16,800/mo ($201,600/yr).
You've now got a revenue figure attached to your load time. Send me the URL and I'll tear down what's actually slowing it, the images, the scripts, the server, and tell you which fixes pay back fastest. Free teardown, and the plan is yours whether you hire me or not.
Plain English
Speed isn't a tech metric. It's a revenue metric.
Load time and conversion rate move in opposite directions, and the relationship is brutally linear. Across large studies, Portent and Deloitte both landed near the same figure: conversions fall roughly 7% for every extra second a page takes to load. The first few seconds do the most damage.
The drop-off is sharpest on mobile, where attention is thin and connections are slower. Google found that 53% of mobile visits are abandoned outright once load time crosses 3 seconds. That's not 53% who convert worse, it's 53% who never see your page at all. A site that loads in 1 second converts roughly 2.5 to 3 times better than one that loads in 5.
This calculator takes that 7%-per-second relationship and applies it to your actual numbers. You enter where you are, where you want to be, and your traffic and order value, and it shows the extra orders and revenue the speedup would unlock every month. The point isn't to admire the lag. It's to price it, so a performance sprint stops competing with 'real' work for budget.
The formula
Extra revenue = Visitors × (Baseline conv % × (1 + 0.07 × seconds saved) − Baseline conv %) ÷ 100 × Order value
Going from 4s to 2s saves 2 seconds, so conversions lift by 0.07 × 2 = 14%. A 3% rate becomes 3.42%. On 50,000 visitors that's 210 extra orders a month; at an $80 order value, $16,800 in revenue you're leaving on the table every single month, purely to load time.
What each second actually costs
The research is remarkably consistent: speed buys conversions, and the steepest losses happen early. Here's how load time maps to real visitor behavior, anchored to the Google/Deloitte and Portent data:
| Load time | Verdict | Conversion vs. fast | Mobile abandonment |
|---|---|---|---|
| 1 second | Elite | Baseline (peak) | Lowest |
| 2 seconds | Strong | ≈ −7% | Low |
| 3 seconds | The cliff edge | ≈ −14% | 53% of mobile leave |
| 4 seconds | Bleeding | ≈ −21% | High |
| 5 seconds | Half lost | ≈ 1/2.5–3× of 1s | Severe |
Source: Google/Deloitte Milliseconds Make Millions + Portent · 2024
The number's big. Where do you start?
You're above the 3s mobile cliff.
This is the emergency. More than half your mobile traffic is abandoning before the page renders. Compress and lazy-load images, defer non-critical JavaScript, and get under 3 seconds before you optimize anything else.
Slow Largest Contentful Paint.
Your hero image or main content block is the bottleneck. Serve next-gen formats (WebP/AVIF), set explicit dimensions, preload the LCP image, and put a CDN in front of it. This is usually the single biggest lever.
Time-to-interactive lags behind paint.
The page looks loaded but doesn't respond. That's heavy JavaScript blocking the main thread. Code-split, ship less, and defer third-party tags (chat widgets, analytics, A/B tools) until after interaction.
Server response (TTFB) is high.
Nothing downstream can be fast if the server is slow to answer. Add caching, move to edge rendering, and audit slow database queries before you blame the front end.
Where the seconds hide
01Fix the images first
Images are the heaviest thing on most pages. Modern formats, correct sizing, and lazy-loading below the fold routinely cut full seconds with zero design change.
02Defer the third parties
Chat widgets, heatmaps, and tag managers load synchronously and block everything. Defer them until after the page is interactive and watch your metrics jump.
03Ship less JavaScript
Every unused KB of JS parses and executes on the main thread. Code-split by route and tree-shake hard, the lightest page is the fastest one.
04Put a CDN in front
Serving assets from an edge node near the visitor shaves latency on every request. It's the highest leverage-per-hour fix for a global audience.
05Cache aggressively
Static pages and assets should be served from cache, not regenerated per request. A good cache turns a slow server into an instant one.
06Preload what matters
Tell the browser about your LCP image and critical fonts early with preload hints, so the most important pixels paint first.
07Cut the redirect chains
Each hop adds a full round trip. Collapse redirect chains and point links at the final URL directly.
08Measure on a real phone
Lab scores lie. Test on a mid-range device on 4G, because that's the visitor whose conversion you're losing at the 3-second cliff.
The vocabulary
- Page load time
- How long a page takes to become usable for the visitor. The single input this calculator turns into lost revenue.
- Conversion rate
- The share of visitors who complete the goal (order, signup, lead). It rises as load time falls.
- LCP (Largest Contentful Paint)
- When the biggest visible element finishes rendering. Google's threshold for 'good' is 2.5 seconds or less.
- TTFB (Time to First Byte)
- How long the server takes to send the first byte of the response. A slow TTFB caps how fast the page can ever be.
- Bounce / abandonment
- A visitor leaving before engaging. 53% of mobile visits abandon when load exceeds 3 seconds.
- AOV (Average order value)
- Revenue per conversion. Multiplying recovered conversions by AOV is what turns speed into dollars.
Page speed questions, straight answers
Roughly 7% for every additional second, per Portent and Deloitte's analyses. That's the figure this calculator uses. The losses are steepest in the first few seconds, and on mobile a 3-second load time is a hard cliff: Google found 53% of mobile visits are abandoned past that point.
Keep going
A calculator tells you what. A call tells you what to do about it.
Send me the account behind these numbers. I'll tell you straight where the money's leaking and what I'd fix first — free, and you keep it whether you hire me or not.