What does downtime actually cost you?
Two quick calculators: how much money an outage burns while your site is down, and what those pretty 99.9% promises mean in real minutes.
Downtime cost calculator
Sales, subscriptions, leads: whatever your site brings in per month.
Napkin math, on purpose: it assumes your revenue arrives evenly around the clock. Your 2 a.m. is probably cheaper than your Black Friday.
Uptime to downtime converter
What providers promise, and what that little number allows them to break.
| Period | Allowed downtime |
|---|---|
| Per day | 1 min 26 s |
| Per week | 10 min 5 s |
| Per month | 43 min 50 s |
| Per year | 8 h 45 min 58 s |
100% uptime does not exist. Whoever promises it hasn't been woken up at 3 a.m. yet.
How the math works
The cost calculator turns your monthly revenue into an hourly rate by dividing it by 730, the hours in an average month. An outage's cost is that hourly rate multiplied by how long you were down.
The yearly projections multiply your hourly rate by the downtime each uptime level allows: 99% lets your site be down almost 88 hours a year, 99.9% about 8 hours and 46 minutes.
The converter is the same formula in reverse: allowed downtime = (100% minus the promised uptime) times the length of the period, using a 30.44-day average month. No industry averages, no invented statistics. Your numbers, your math.
Common questions
How much downtime is 99.9% uptime?
About 8 hours 46 minutes per year, or roughly 43 minutes per month. Sounds tiny until it lands in the middle of your product launch.
Is this calculator accurate for my business?
It's an honest estimate, not an invoice. It spreads your revenue evenly across every hour, and real traffic has peaks and valleys. Use your own numbers and treat the result as the order of magnitude, not the exact peso.
How do I make downtime cost less?
You can't prevent every outage, but you control how long one lasts before you know about it. A monitor that checks your site and alerts you immediately turns an afternoon of silent losses into a five-minute fix. OhSnap does exactly that, free for up to 5 sites.
Now you know the cost. Shrink it.
OhSnap tells you the moment your site goes down, before your customers do. Free for 5 monitors, alerts included.