NigeriaPolls · Interactive Tool
Poll of Polls Calculator
Combine any set of polls into one weighted average. Enter each poll's sample size, age and results, and the calculator applies sample-size and recency weighting and shows the combined sampling error.
Aggregate your own polls
Name your options, then enter each poll you want to combine with its sample size, its age in months and the percentage it reported for each option. Leave an option blank if a poll did not include it.
| Poll | Sample size | Months ago | |||||
|---|---|---|---|---|---|---|---|
Your weighted average
Enter at least one poll with a sample size to see the weighted average.
How It Works
The Method Behind a Poll Average
A good poll average is transparent and reproducible. These are the three steps the calculator follows.
Sample-size weighting
Polls with larger samples have smaller sampling error, so they carry more weight. A poll of 2,000 people counts for twice as much as a poll of 1,000 when all else is equal. This stops one small poll from pulling the average off course.
Recency weighting
Opinion moves, so newer polls count for more. The weight decays smoothly with age: a poll one month old keeps about 86% of its weight, and a poll six months old keeps about 41%.
Combined sampling error
Pooling the samples shrinks the random sampling error. The calculator reports it at 95% confidence, as a guide to how far the average could sit from the true value from sampling alone.
Aggregation formula
weight_i = sample_i × exp(−0.15 × months_ago_i)
average = Σ(weight_i × result_i) / Σ(weight_i)
sampling error ≈ 98 / √(Σ sample_i)
See the methodology page for how NigeriaPolls designs its own samples and publishes its results.
Before You Combine
What to Check Before Including a Poll
Same question
Only combine polls that ask the same question in a similar way.
Same population
Keep all-adult, registered-voter and likely-voter samples apart.
Published method
Use polls that publish question wording, field dates, sample size and mode.
Field dates, not release dates
Measure a poll's age from when interviews were done, not when it was reported.
Frequently Asked Questions
What is a poll of polls?
A poll of polls combines the results of several independent polls into one estimate. Any single poll can be thrown off by sampling noise, timing or the way a pollster runs fieldwork. Averaging across polls, weighted by sample size and recency, smooths out that noise and gives a steadier picture of public opinion.
How are the polls weighted in this calculator?
Each poll gets a weight equal to its sample size multiplied by a recency decay, exp(-0.15 x months old). Larger and newer polls count for more. The weighted average for each option is the sum of weight times result, divided by the sum of weights.
How is the combined sampling error worked out?
The calculator adds the sample sizes of the polls you enter and applies the standard 95% sampling error formula for a simple random sample, about 98 divided by the square root of the total sample, in percentage points. It is a guide to random sampling error only. It does not cover non-response, question wording, differences between pollsters or late shifts in opinion.
Which polls should I include?
Include polls that publish their question wording, field dates, sample size and method, and that ask the same question of the same population. Do not mix vote-intention polls with approval polls, and keep likely-voter and all-adult samples apart.
Does the aggregate predict an election result?
No. An aggregate describes opinion at the time of the polls. Turnout, undecided voters and campaign events all move results before election day. Treat it as a snapshot. For election information, visit the 2027 Election Hub.
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