Effect Size Calculator

Calculate Cohen's d and other effect size measures. Use this free browser-based effect size calculator from XTRAW Tools.

Effect Size Calculator helps you calculate Cohen's d and other effect size measures. Use this free browser-based calculator from XTRAW Tools to compare inputs, estimate results, and plan your next step.

How to Use the Effect Size Calculator

Enter the required calculator inputs shown in the form.
Review the probability, experiment, sample, velocity, acceleration, distance, force, angle, or physics assumptions.
Run the calculator, then adjust one input at a time to compare scenarios or check your estimate.

What This Calculator Helps With

Calculate Cohen's d and other effect size measures. It is designed for students, teachers, researchers, analysts, healthcare reference users, and anyone reviewing effect sizes or research statistics who want a fast, browser-based estimate before relying on a spreadsheet, textbook, analytics platform, physics software, research software, professional source, or specialist.

Mean 1 (x̄₁): 52
Mean 2 (x̄₂): 48
Std Dev 1 (s₁): 10
Std Dev 2 (s₂): 9
Sample Size 1 (n₁): 30
Sample Size 2 (n₂): 30

Common Uses

People use this calculator when they need a quick way to estimate standardized differences or compare research-study assumptions.

Math Solving: Solve probability, combinatorics, A/B testing, effect size, physics, motion, force, or work formulas from entered values.
Measurement: Measure odds, combinations, conversion lift, effect size, velocity, acceleration, force, work, range, or related computed values.
Project Planning: Plan lessons, experiments, research, STEM assignments, campaign tests, or analysis workflows using transparent formulas.

Formula or Method

Cohen's d = (x̄₁ − x̄₂) / s_pooled; |d|: 0.2=small, 0.5=medium, 0.8=large

Example

Example inputs: Mean 1 (x̄₁): 52; Mean 2 (x̄₂): 48; Std Dev 1 (s₁): 10; Std Dev 2 (s₂): 9; Sample Size 1 (n₁): 30; Sample Size 2 (n₂): 30

Example result: Using the default inputs, pooled standard deviation is 9.51 and Cohen's d is 0.42.

Related Tools

Effect Size Calculator FAQ

Is the Effect Size Calculator free?

Yes. This calculator is free to use on XTRAW Tools.

Do I need to create an account?

No. XTRAW tools are designed for browser-based use without requiring an account.

Are the results exact?

Results may be estimates depending on the inputs, formula, rounding, selected method, probability model, physics assumption, or purpose of the calculator. Always verify important results before relying on them.

Disclaimer: This calculator is provided for general informational, educational, and convenience purposes only. It is not medical, clinical, academic, research, statistical consulting, legal, financial, or professional advice. Always verify important results with a qualified professional, instructor, statistician, researcher, clinician, or authoritative source before making decisions.