Project Campaign
Sampling Calculator

Ward sample size calculator.

Use this page to estimate how many voters or households should be sampled in each ward or polling district. The default settings use a 95% confidence level, a 5% margin of error, and the standard worst-case assumption of 50/50 support.

Assumptions

Calculation settings

Initial large-population sample
384

This is the unadjusted sample size before finite population correction.

Formula
n₀ = Z² × p(1-p) / E²

Finite population correction is then applied to each ward total.

Interpretation

Higher confidence or lower margin of error means larger samples. Larger wards still level off once totals reach the low thousands.

Ward Inputs

Repeat for each ward

Add or edit rows below. The calculator updates sample sizes for voters and households automatically.

Calculator values will be stored on the server.
Ward Voters Homes Voter Sample Household Sample Actions