Daniel Oh
Featured contributor MSc Applied Statistics; 7 years in analytics and data tooling.

Daniel Oh

Senior Contributor, Math & Statistics

0 calculators 0 articles Member since Jun 2026
Math / Percentage

Harmonic Mean Calculator

Compute the harmonic mean of a list of positive numbers — useful for averaging rates such as speeds or ratios.

basic
2,653 4.5 1 min
Math / Percentage

Geometric Sequence Calculator

Compute the n-th term and the sum of the first n terms of a geometric sequence from its first term and common ratio.

basic
5,721 4.8 1 min
Math / Percentage

One-Sample t-Test Calculator

Compute the t-statistic and degrees of freedom for a one-sample t-test from the sample mean, the population mean under H...

basic
4,849 4.9 1 min
tutorial Math

Percentages Without the Headache

Every "X% of Y" problem, every "what percent of", every percent-change question — written out the way you'd actually say them.

Daniel Oh Daniel Oh
3 min

Reviewed by Daniel Oh

These calculators were technically reviewed by Daniel Oh for accuracy.