What is Cohen d and how do you interpret it?

Cohen d = (mean1 - mean2) / pooled_SD. Interpretation: d=0.2 small effect, d=0.5 medium, d=0.8 large. A statistically significant result with d=0.05 may be practically insignificant (e.g. 1% revenue improvement). Always report both p-value and effect size.

How do you calculate pooled standard deviation?

Pooled SD = sqrt(((n1-1)*SD1^2 + (n2-1)*SD2^2) / (n1+n2-2)). For equal groups: simply average the variances. Pooled SD accounts for different group sizes. If groups are very unequal (10:1 ratio), use Welch t-test which does not assume equal variances.

t-Test Effect Size Calculator (Cohen d)

Calculate Cohen d effect size for t-tests. Interpret practical significance beyond statistical significance for business decision-making.

Networking

Algorithms

Binary & Number

Systems

Dev Metrics

IP Subnet Calculator

IP Address

CIDR Prefix

Network

192.168.1.0

Broadcast

192.168.1.255

Subnet Mask

255.255.255.0

First Host

192.168.1.1

Last Host

192.168.1.254

Usable Hosts

254

Binary breakdown:

IP: 11000000.10101000.00000001.00000000

Mask: 11111111.11111111.11111111.00000000

Net: 11000000.10101000.00000001.00000000

How to Use

Enter the values for the patient or scenario you are assessing. Calculate Cohen d effect size for t-tests. Interpret practical significance beyond statistical significance for business decision-making. Use the t-test effect size result to inform your clinical assessment.

Related Calculators

Chi-Square Test

AI & Technology

Sample Size for Power

AI & Technology

ANOVA F-Statistic

AI & Technology

t-Test Effect Size Calculator (Cohen d)

IP Subnet Calculator

How to Use

Related Calculators

Frequently Asked Questions

What is Cohen d and how do you interpret it?

How do you calculate pooled standard deviation?