Success Rate Calculator
Enter total attempts and successful outcomes to instantly calculate success rate, failure rate, unsuccessful attempt count, ratio, and gap vs your target — for sales, ads, quality control, hiring funnels, or any attempt-based metric.
Quick preset
Attempt data
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Step-by-step
What this calculator does
This success rate calculator takes total attempts and successful outcomes and returns five metrics: success rate, failure rate, failed attempt count, success-to-failure ratio, and the gap between your current result and a target rate. The gauge bar shows success vs failure visually, with a target marker so you can see at a glance whether you are above or below your benchmark.
It works for any attempt-based metric — sales close rate, ad conversion rate, quality pass rate, hiring funnel yield, medical procedure success, A/B test win rate, or sports win percentage.
Success rate formula
Failure Rate = 100 − Success Rate
Failed Attempts = Total Attempts − Successful Attempts
Gap vs Target = Success Rate − Target Rate
(positive = above target · negative = below target)
How to use
- Select a preset or enter your own total attempts and successful attempts.
- Set a target rate if you have a benchmark to compare against. Leave at 0 to skip.
- Click Calculate — the gauge bar, metric cards, and interpretation update instantly.
- Read the "What this means" card for context on whether this rate is strong, moderate, or needs attention.
Example calculations
Success: 36% · Failure: 64%
Gap: 4% below target
Success: 4.5% · Failure: 95.5%
Gap: 0.5% below target
Success: 97.4% · Failure: 2.6%
Gap: 0.6% below target
Success: 100% · Failure: 0%
Gap: 5% above target
FAQ
What is the success rate formula?
Success Rate = (Successful Attempts ÷ Total Attempts) × 100. Divide successful outcomes by total attempts and multiply by 100 to convert to a percentage. Failure rate is simply 100 minus the success rate.
What is a good success rate?
It depends entirely on the context. A 2–5% conversion rate is typical for cold email outreach. A 97–99% pass rate is expected for manufacturing quality control. A 50%+ close rate is strong for warm sales leads. Always benchmark against industry norms or your own historical performance rather than a universal number.
What is the difference between success rate and conversion rate?
They are calculated the same way — both are (successes ÷ total) × 100. The difference is context: conversion rate is typically used in marketing and sales funnels, while success rate is a broader term applied in quality control, healthcare, sports, research, and any situation where a binary outcome is being tracked.
Can a high success rate be misleading?
Yes, in two ways. First, a high rate on a very small sample may not be statistically reliable — 9 out of 10 looks like 90% but has wide variance. Second, cherry-picking attempts (only calling warm leads, only testing easy cases) inflates the rate without reflecting true performance. Always review rate alongside total volume and how attempts were selected.
How does the gap vs target work?
Gap = Success Rate − Target Rate. A positive gap means you are above your target. A negative gap means you are below. If you set a target of 40% and your success rate is 36%, the gap is −4% — you need 4 more percentage points to hit the benchmark.
How many attempts do I need for a reliable success rate?
As a rule of thumb, at least 30 attempts is a minimum for any pattern to emerge, and 100+ gives much more reliable results. For rates below 10% (like ad conversion), you typically need several hundred to several thousand attempts before the rate stabilizes. Small samples can swing dramatically from one period to the next.
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Disclaimer: This calculator provides simple percentage calculations for planning and tracking purposes only. It does not account for statistical significance, confidence intervals, sample bias, seasonality, or weighting. Results may not reflect true performance without adequate sample size and consistent definition of success.