Confidence interval calculator
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Calculate confidence intervals online with ease
Estimate population parameters with confidence intervals. Perfect for inferential statistics and understanding the reliability of your sample estimates.
Analyze csv, parquet, tsv and json in seconds
Calculate confidence intervals at different levels
Get margin of error and standard error
Visualize data distribution with CI bounds
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Perfect for statistical inference
How to calculate confidence intervals online
- Upload your data
Use the input box at the top of the page to upload your dataset - Select a column
Choose the numerical column you want to analyze - Choose confidence level
Select your desired confidence level (90%, 95%, or 99%) - View results
See the confidence interval bounds and related statistics - Analyze visualization
Use the distribution plot to understand your data and confidence interval
Example confidence intervals for different distributions
Normal distribution
A normal distribution shows symmetric confidence intervals around the mean, providing the most reliable interval estimates.
95% Confidence interval:
- Lower bound: 9.93
- Upper bound: 10.06
- Mean: 9.99
- Margin of error: 0.06
Uniform distribution
A uniform distribution demonstrates how confidence intervals work with bounded, evenly distributed data.
95% Confidence interval:
- Lower bound: 9.82
- Upper bound: 10.19
- Mean: 10.01
- Margin of error: 0.18
Bimodal distribution
A bimodal distribution shows how confidence intervals handle data with two distinct peaks, resulting in wider intervals.
95% Confidence interval:
- Lower bound: -0.20
- Upper bound: 0.06
- Mean: -0.07
- Margin of error: 0.13
Student's t-distribution
A t-distribution with 3 degrees of freedom shows how confidence intervals adapt to heavy-tailed data, resulting in wider intervals.
95% Confidence interval:
- Lower bound: -0.05
- Upper bound: 0.16
- Mean: 0.06
- Margin of error: 0.10
Mixed normal distribution
A mixture of normal distributions with different variances shows how confidence intervals handle complex, multi-modal data.
95% Confidence interval:
- Lower bound: 4.96
- Upper bound: 5.04
- Mean: 5.00
- Margin of error: 0.04
Exponential distribution
An exponential distribution demonstrates how confidence intervals behave with highly skewed, right-tailed data.
95% Confidence interval:
- Lower bound: 1.89
- Upper bound: 2.13
- Mean: 2.01
- Margin of error: 0.12
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