A3 Residents Survey Calculators

Use these tools to check the precision of your survey results, or to work out how many completed surveys you should aim for. Both calculators use a 95% confidence level, as specified in the programme guidance.

Margin of Error

How precise is your survey result? Enter your completed surveys and an observed finding to see the margin of error.

Number of Completed Surveys Your achieved sample size

Survey Result — % (optional)

Enter a whole number, e.g. 72 for "72% satisfied". Leave blank to use 50% (worst case).

Total Population Size (optional) Enter if your sample exceeds 5–10% of your population — FPC will be applied automatically

Margin of error

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Lower bound

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Upper bound

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Surveys used

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ℹ A margin of error of ±5% or lower is ideal. Above ±10%, it is difficult to draw reliable conclusions. Results close to 50% always have a larger margin of error — leaving the survey result blank tests the worst case.

or work out your target

Target Number of Completed Surveys

How many surveys do you need? Enter your population size and desired precision to get a minimum target.

Total Population Size Number of households that received measures

Desired Margin of Error — ±5%

±5%

±5% is ideal; ±10% is the maximum for reliable conclusions

Apply Finite Population Correction (FPC) — tick if your sample is likely to exceed 5–10% of the population

Minimum surveys required

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Population

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Response rate needed

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ℹ Always aim for more responses than the minimum — non-response is common. A response rate of 20–30% is typical for postal or online surveys, so plan your outreach accordingly. Learn more about FPC →