This margin of error reference table shows the margin of error for a range of sample size values, assuming a proportion of 0.5 and a confidence level of 95% (z = 1.96). Every figure is computed with the same engine that powers our Margin of Error Calculator, so the numbers are exact.
| Sample size | Margin of error |
|---|---|
| 250 | 6.20% |
| 500 | 4.38% |
| 750 | 3.58% |
| 1,000 | 3.10% |
| 1,500 | 2.53% |
| 2,000 | 2.19% |
| 3,000 | 1.79% |
| 5,000 | 1.39% |
| 7,000 | 1.17% |
| 10,000 | 0.98% |
How to use this table
Find the row closest to your sample size and read across to the margin of error. For a value between two rows, the real figure sits between them — or enter your exact numbers in the Margin of Error Calculator for a precise answer.
Need a value that is not in the table? — the Margin of Error Calculator does it instantly, for free, with the formula and a worked example built in.
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