Meta-analysis Effect Converter
Convert ratios, log effects, CIs, p-values, medians and SMDs for meta-analysis.
Enter your values to see the result.
Median-based estimates use Luo et al. (2018) for the mean and Wan et al. (2014) for the SD; they assume roughly symmetric data. Leave minimum and maximum blank if you only have the IQR. Results use standard large-sample formulas and are meant to support, not replace, a statistician's review. Check the assumptions behind each method before you report the numbers.
Continue your work
- I² Heterogeneity Calculator — Pool the converted effects and check I².
- Effect Size Calculator — Calculate d from group summaries.
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How to use the Meta-analysis Effect Converter
Convert ratios, log effects, CIs, p-values, medians and SMDs for meta-analysis.
- 1 Choose the conversion you need.
- 2 Enter the published figures, such as a ratio with its CI or a median with quartiles.
- 3 Copy the log effect, standard error or estimated mean and SD.
Example and practical tips
An odds ratio of 1.8 (95% CI 1.2 to 2.7) becomes ln(OR) = 0.588 with a standard error of 0.207.
Further reading
Frequently asked questions
How are means estimated from medians?
The mean uses Luo et al. (2018) and the SD Wan et al. (2014), which work for the median with the IQR, the range or both.
Why use log ratios?
Ratios are skewed. On the log scale they are symmetric, so they can be pooled with inverse-variance weights.
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