Recommended Sample Sizes
Error Associated with Samples of Given Sizes*
\
Size of Sample Error Associated with Percentage Estimates
| 100 | +/- 10% | |
| 150 | +/- 8% | |
| 200 | +/- 7% | |
| 250 | +/- 6% | |
| 300 | +/- 6% | |
| 350 | +/- 5% | |
| 400 | +/- 5% | |
| 450 | +/- 5% | |
| 500 |
+/- 4% |
|
| 600 | +/- 4% | |
| 700 | +/- 4% | |
| 800 | +/- 4% | |
| 900 | +/- 3% | |
| 1000 | +/- 3% | |
*Presumes the individuals selected were selected by chance by the researcher. The estimates do not include error attributable to measurement or other survey errors.