| Sample size for the 95% confidence level | ||||||
| ±3% sampling error | ±5% sampling error | ±10% sampling error | ||||
| 50/50 split | 80/20 split | 50/50 split | 80/20 split | 50/50 split | 80/20 split | |
| 100 | 92 | 87 | 80 | 71 | 49 | 38 |
| 200 | 169 | 155 | 132 | 111 | 65 | 47 |
| 400 | 291 | 253 | 196 | 153 | 78 | 53 |
| 600 | 384 | 320 | 234 | 175 | 83 | 56 |
| 800 | 458 | 369 | 260 | 188 | 86 | 57 |
| 1000 | 517 | 406 | 278 | 198 | 88 | 58 |
| 2000 | 696 | 509 | 322 | 219 | 92 | 60 |
| 4000 | 843 | 584 | 351 | 232 | 94 | 61 |
| 6000 | 906 | 613 | 361 | 236 | 95 | 61 |
| 8000 | 942 | 629 | 367 | 239 | 95 | 61 |
| 10,000 | 965 | 640 | 370 | 240 | 95 | 61 |
| 20,000 | 1013 | 661 | 377 | 243 | 96 | 61 |
| 40,000 | 1040 | 672 | 381 | 244 | 96 | 61 |
| 100,000 | 1056 | 679 | 383 | 245 | 96 | 61 |
| 1,000,000 | 1066 | 683 | 384 | 246 | 96 | 61 |
| 1,000,000,000 | 1067 | 683 | 384 | 246 | 96 | 61 |