Free tools that turn downtime, SLAs, and recovery targets into money and time budgets — so CTOs, SREs, and founders can decide with numbers, not slogans.
Example: If shortfall = 0.23%, Tier 2 (10%) → $100,000 on $1,000,000.
Enter contract details, downtime duration, and other relevant metrics into our intuitive forms.
Adjust penalty tiers, revenue models, or recovery costs to match your specific scenario.
Get instant, precise calculations of financial impact based on your inputs.
Generate a clean summary report as a PNG to share with stakeholders.
An SLA is a Service Level Agreement. It is a promise about how available a service should be. For example, a vendor may promise 99.95% uptime.
If the service is down more than the allowed time, the vendor may owe you a service credit. A service credit usually reduces a future invoice. It is often not cash.
This calculator helps you estimate that credit. It uses your contract value, your promised uptime, your real downtime, and your penalty tiers.
Contract value: $1,000,000 per month
Promised uptime: 99.95%
Period: 30 days
Allowed downtime: 21.6 minutes
Real downtime: 90 minutes
Your uptime is below the promise. The shortfall is about 0.16 percentage points. If your tier for that shortfall is 10%, the estimated credit is $100,000.
Always check your real contract. Vendor rules can be different.
See the full downtime tables: SLA uptime → downtime reference. Or convert any SLA with the Allowed Downtime Calculator.
CTOs, DevOps engineers, SRE teams, procurement, and founders who buy cloud or SaaS services. You do not need to be a lawyer. You only need clear numbers for a discussion.
If English is not your first language, keep the example simple: one contract value, one uptime target, one downtime number. Then change one input at a time.
Here is the same idea with euros. Many European contracts use EUR and calendar months. The math does not change. Only the currency symbol changes.
Contract value: €40,000 per month (your SaaS or cloud fee)
Promised uptime: 99.9%
Period: 30 days (43,200 minutes)
Allowed downtime: 0.1% of 43,200 = 43.2 minutes
Real downtime: 120 minutes (from your monitoring tool)
You used 120 minutes. The SLA only allowed 43.2 minutes. You are over the limit.
Suppose your contract says: if monthly uptime falls below 99.9% but stays at or above 99.0%, you get a 15% service credit.
Estimated credit ≈ 15% × €40,000 = €6,000 off a future invoice.
This is a planning estimate. Your vendor may round differently, exclude maintenance, or require a claim form within a fixed number of days.
Try the calculator with €40,000, 99.9%, and 120 minutes. Then change only one input. For example, try 90 minutes instead of 120. You will see how credits move when downtime changes.
Shortfall means how far you missed the uptime promise. It is not the same as total downtime minutes. First you convert downtime into an uptime percent. Then you compare that percent to the promise.
Simple idea:
Example shortfall table (30-day month)
| Real downtime | Actual uptime | Promise | Shortfall |
|---|---|---|---|
| 21.6 min | 99.95% | 99.95% | 0 (on target) |
| 43.2 min | 99.90% | 99.95% | 0.05 pp |
| 90 min | ~99.79% | 99.95% | ~0.16 pp |
| 216 min | 99.50% | 99.95% | 0.45 pp |
“pp” means percentage points. A drop from 99.95% to 99.79% is a shortfall of 0.16 percentage points — not “0.16% of the fee” by itself. The fee percent comes from your credit tiers.
Vendors often map shortfall bands to credit percents. Example: 0–0.1 pp shortfall → 10% credit; larger shortfall → 25% credit. Always copy the bands from your PDF. Do not invent them.
A claim needs evidence. “We felt the site was slow” is not enough. Good proof comes from systems that watch the service from the outside and from the inside.
External monitoring checks your URL or API from the public internet. It records when the check fails. Many teams use tools that ping every 1 or 5 minutes.
Internal monitoring watches servers, queues, and error rates inside your stack. It helps explain why something failed. Vendors still care a lot about customer-visible downtime.
To support an SLA claim, collect:
Be careful with false alarms. A monitor in one city can fail while users in other cities are fine. Your contract may define downtime as “unavailable for all users” or “failed health checks from two regions.” Read that line. Then match your proof to that definition.
Also separate degraded service from down service. Slow pages may hurt revenue, but they may not count as SLA downtime unless the contract says so. Write that difference in your notes before you open a claim.
This calculator helps with steps 5 and 6. It does not replace your contract text or your evidence pack.
People sometimes mix these two ideas. They are not the same.
Example: your outage costs the business €50,000 in lost sales. The SLA credit might be only €6,000. Insurance might cover more, but only if the event matches the policy and you filed correctly.
Use this calculator for vendor credit estimates. Use a downtime cost calculator for business loss estimates. Talk to your insurer (or broker) for insurance questions. Do not treat an SLA credit as full insurance.
In those cases, pause. Gather facts first. Or use a simpler tool to convert uptime into allowed minutes, then come back.
Full minute tables by uptime target: SLA uptime → downtime reference.
Tables for 28-, 29-, 30-, and 31-day months: Calendar-month SLA downtime tables.
Convert any percent into allowed minutes yourself: Allowed Downtime Calculator.
Longer reading on credits and negotiation: Ultimate guide to SLA penalties.
Remember: unique numbers beat generic averages. Your contract, your monitors, and your month length are the three inputs that matter most.
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Our SLA Penalty Calculator works by taking your contract value, promised uptime percentage, and actual downtime duration to calculate the financial penalty based on your SLA agreement. You can customize penalty tiers to match your specific contract terms.
Website downtime costs are influenced by factors such as lost revenue (e.g., e-commerce sales), decreased employee productivity, potential SLA penalties, and long-term reputational damage. Our calculator considers these factors to provide a comprehensive cost estimate.
Yes, you can fully customize penalty tiers, contract values, uptime percentages, and other parameters to match your specific SLA agreement and business requirements.
Yes, all calculations are performed locally in your browser. We don't store or transmit any of your sensitive contract or business data to our servers.
Currently, we support USD and EUR currencies. More currencies will be added based on user demand.
Shortfall is the gap between the uptime the vendor promised and the uptime you actually got. Example: promise 99.95%, actual 99.79%. The shortfall is about 0.16 percentage points. Your contract then maps that gap to a credit percent (for example 10% of the monthly fee). Shortfall is not the same as “total minutes down.” Minutes matter, but the credit table usually keys off the uptime percent or the size of the miss.
Almost always yes. Vendors ask for proof with start and end times, often in UTC. Export checks from an external monitor, note which URLs failed, and remove minutes the contract excludes (such as announced maintenance). File inside the claim window written in the SLA — many contracts give only 15–30 days after the month ends. This calculator estimates the money. Your logs prove the downtime.
No. An SLA credit is usually money off a future invoice from that vendor. It is capped and often much smaller than your real business loss. Insurance is a separate product that may cover larger interruption losses after its own rules and deductibles. Use this tool for credit estimates. Use a downtime cost estimate for business impact. Ask your insurer about policy cover. Do not assume a 10% invoice credit will make you whole.
Eighteen free tools: SLA, downtime cost, RTO/RPO, allowed downtime, cost of nines, error budget, reliability ROI, SLA claim pack, post-mortem generator, cron generator, status page builder/templates/free status page, availability checker, SSL checker, REST API checker, DNS analysis, and a webpage speed smoke test. Start at the Free Tools hub.
Open the Free Tools hub (also linked in the header and footer). For money and planning paths, use the Reliability Money Toolkit.
No. They are honest single-location smoke tests for quick checks. For continuous monitoring and hosted status pages, use dedicated monitoring later — our generators help you document and communicate incidents today.