Stratified Sample Calculator

Allocate a total sample proportionally or by Neyman allocation across strata, using largest-remainder rounding to preserve the requested total.

The Stratified Sample Calculator allocates a requested total sample across 3 to 8 strata. Leave all standard-deviation fields blank for proportional allocation, or enter an SD for every stratum to use Neyman allocation. Largest-remainder rounding keeps the displayed whole-number allocations equal to the requested total.

The result is an allocation plan based on stratum sizes and, optionally, supplied standard deviations; it does not estimate within-stratum variability.

Enter the total whole-number sample size.
Enter the population size for every stratum.
Leave every SD blank for proportional allocation, or fill all SDs for Neyman allocation.
Review each rounded allocation and the displayed total.

Stratified allocation formulas

Proportional: nₕ = nNₕ / ΣN.

Neyman: nₕ = nNₕSₕ / Σ(NⱼSⱼ).

Largest-remainder rounding assigns any remaining units by descending fractional remainder; ties go to the earlier row.

Reading stratified allocations

The method and total are shown

The method label identifies proportional or Neyman allocation. Each stratum displays its whole-number allocation and unrounded value; the allocated total is shown for a direct check against n.

Statistics tips and best practices

Enter positive whole-number population sizes for all strata.
Use SDs measured on the same outcome scale when applying Neyman allocation.
Keep the tie rule in mind when small samples produce equal fractional remainders.

Common mistakes to avoid

Entering an SD for only some strata.
Entering a total sample larger than the combined population.
Assuming rounded stratum allocations can be rounded independently without changing their sum.

This is a sample-allocation calculation, not a survey analysis. It uses only the stratum sizes and optional SDs entered and does not estimate response, cost, or design effects.