Convert an SLA percentage into allowed downtime per day, month, and year, and estimate the financial SLA credit owed when actual measured uptime falls short of your promised SLA.
| SLA | Per Day | Per Month | Per Year |
|---|
Enter your details and click Calculate to see results
Service Level Agreements express reliability as a percentage — 99.9%, 99.99%, and so on — but percentages are hard to reason about intuitively. This SLA calculator translates any SLA percentage into concrete allowed downtime (in hours, minutes, and seconds per day, month, and year), compares it against your actual measured uptime, flags whether the SLA was breached, and estimates the financial credit a provider would typically owe you under common tiered-credit contract structures.
It computes allowed downtime at the promised SLA by subtracting the SLA fraction from 100% and multiplying by the total seconds in a day, month, and year, then does the same for your actual measured uptime. It compares actual downtime to allowed downtime to determine breach status, and applies an illustrative tiered credit schedule against your monthly bill to estimate the credit owed.
DevOps and SRE teams tracking SLA compliance, procurement teams evaluating a vendor's uptime promise before signing, SaaS companies drafting their own customer-facing SLA, and anyone who experienced an outage and wants to estimate what credit they're owed all need this downtime-to-credit math.
A single percentage point of uptime can represent a difference of hours per month in real downtime, and most SLA contracts pay compensation only in service credits — not cash — often capped and only issued if the customer proactively files a claim within a specific window. Understanding exactly how much downtime your SLA promises, how far your actual measured uptime fell short, and what credit you're contractually owed helps you hold providers accountable and negotiate better terms, whether you're a customer of a cloud provider or the one offering an SLA to your own customers.
How this calculator turns an SLA percentage into downtime and a credit estimate
This calculator uses an exact 30-day month (2,592,000 seconds) and 365-day year for its period totals — some industry references instead use a 30.44-day average month, which produces slightly different "43 minutes 50 seconds"-style figures for 99.9% uptime.
Availability tiers are informally called "nines" — 99% is "two nines," 99.9% is "three nines," 99.999% is "five nines." Each additional nine reduces allowed downtime roughly 10-fold.
Most SLA remedies are service credits applied to a future invoice, not cash refunds, and are usually capped at 100% of the affected billing period.
Scheduled maintenance, customer-caused outages, and force majeure events are typically excluded from SLA downtime calculations by contract.
From selecting your SLA tier to reading your credit estimate
Choose the SLA percentage your provider promises — 99%, 99.5%, 99.9%, 99.95%, 99.99%, or 99.999% — from the dropdown.
Type the uptime percentage actually measured over the billing period, from your own or your provider's monitoring.
Enter the dollar amount you're billed for the service each month, used to estimate the credit owed if the SLA was breached.
The calculator converts both percentages into allowed and actual downtime, flags a breach if actual uptime fell short, and estimates a tiered credit.
See allowed downtime per day/month/year, your SLA status, the credit tier applied, and a comparison table across all 6 common SLA tiers.
Using the calculator's own default scenario — 99.9% promised SLA, 99.5% actual uptime, $1,000 monthly bill
Suppose your provider promises 99.9% uptime, but you measured 99.5% actual uptime last month, and your monthly bill is $1,000.
Explanation: The actual downtime (3 hours 36 minutes) is roughly 5x the allowed downtime (43 minutes) at the promised 99.9% SLA, confirming a breach. Under this calculator's illustrative tiered schedule, that lands in the 10% credit bracket since actual uptime stayed at or above 99% — a modest $100 credit on a $1,000 bill, which is exactly why reading your actual contract's real thresholds matters before assuming a bigger payout.
What your breach status and credit tier generally imply
| Actual Uptime vs Promise | Status | Recommended Next Step |
|---|---|---|
| At or above promised SLA | SLA Met | No action needed; continue monitoring |
| Below promise, ≥99% | Minor breach | File a claim for the illustrative 10% tier if your contract matches |
| 95% – 99% | Moderate breach | File a claim; consider escalating if repeated |
| Below 95% | Severe breach | File a claim for the full credit; consider vendor review |
If your SLA was breached: check your actual contract's credit schedule and claim deadline — this calculator's 10%/25%/100% tiers are illustrative, and most providers require you to proactively file a claim within a set window.
If your SLA was met: no credit applies under most contracts, even if downtime felt disruptive — SLA credits are tied to the measured percentage, not the subjective impact of an outage.
This tool provides an estimate based on illustrative industry-common tiers, not your specific legal agreement. Always consult your actual SLA document.
This calculator is for estimation and negotiation reference only. It is not a substitute for your actual SLA contract, which defines the real credit tiers, caps, and claim procedures that apply to your agreement.
Where converting SLA percentages into concrete numbers genuinely helps
Quickly check whether a recent outage breached your SLA and estimate the credit owed.
Compare what different SLA tiers actually allow before signing a new vendor contract.
Understand exactly what downtime commitment you're making to your own customers.
Translate raw uptime percentages into concrete downtime figures for internal reports.
Compare downtime allowances across cloud, CDN, and SaaS vendors side by side.
Decide what SLA tier a new internal service should target based on tolerable downtime.
Bring concrete downtime numbers into a vendor negotiation instead of abstract percentages.
Quantify an incident's SLA impact as part of a post-mortem report.
Estimate expected credits before reconciling them against an actual provider invoice.
Use it in a course to make "nines" and downtime tradeoffs concrete for students.
Assess whether a vendor's SLA tier matches your application's actual reliability needs.
Re-run the numbers each billing period to track SLA compliance trends over time.
What this SLA calculator does well, and where it can't replace your actual contract
Allowed downtime for each common SLA tier (exact 30-day month, 365-day year)
| SLA | Per Day | Per Month | Per Year |
|---|---|---|---|
| 99% ("two nines") | 00:14:24 | 07:12:00 | 87:36:00 |
| 99.5% | 00:07:12 | 03:36:00 | 43:48:00 |
| 99.9% ("three nines") | 00:01:26 | 00:43:12 | 08:45:36 |
| 99.95% | 00:00:43 | 00:21:36 | 04:22:48 |
| 99.99% ("four nines") | 00:00:09 | 00:04:19 | 00:52:34 |
| 99.999% ("five nines") | 00:00:01 | 00:00:26 | 00:05:15 |
Summary: This SLA calculator converts any SLA percentage into concrete downtime figures, flags breaches against your actual measured uptime, and estimates an illustrative credit owed — turning abstract "nines" into numbers you can act on. Pair it with the Uptime Percentage Calculator and Cloud Cost Calculator for a fuller infrastructure reliability and budgeting picture.
Common questions about SLA calculator estimates
Official documentation to complement this calculator — not a substitute for your legal contract
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