Free tool
t-test calculator
From means, SDs and sample sizes: t, df, p, the effect size with its confidence interval, and the sentence for your Results.
t-test from means, SDs and sample sizes
You get the APA 7 sentence to paste, with the effect size and its confidence interval where one applies.
The full reporting rules, with a worked example, are in the guide on how to report an independent t-test in APA. Have the SPSS output instead? Paste it into the SPSS to APA converter.
Questions
Student's or Welch's t-test?
Welch's t-test does not assume the two groups have equal variances, and many statisticians now use it by default; it loses almost nothing when the variances are equal. If your groups have clearly different SDs or sizes, choose Welch.
What do I need for a paired t-test?
The mean and SD of the differences (after minus before, for each person) and the number of pairs. The means of the two time points alone are not enough, because the test depends on how the differences vary.
Why Hedges' g and not Cohen's d?
Hedges' g is Cohen's d with a small-sample correction; the two are almost identical above about 20 per group. APA asks for an effect size with its confidence interval, which the calculator gives.
How do I report it in APA 7?
Give t with its df, the exact p (p < .001 when smaller), and the effect size with its 95% CI, for example t(48) = -2.76, p = .008, g = -0.77, 95% CI [-1.33, -0.20].