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

About

Daniel writes and reviews the math and statistics calculators. His explainers lean on worked examples, clean formulas, and obvious edge cases so readers can copy the logic straight into a spreadsheet.

He previously worked as a data scientist at a consumer-tech startup before moving into full-time writing and tooling.

Areas of expertise

Statistics Probability Percentages Data analysis

Education & credentials

BSc Mathematics — University of Toronto
MSc Applied Statistics — ETH Zürich

Math / Geometry

Cube Volume Calculator

Compute the volume, surface area, face diagonal, and space diagonal of a cube from its edge length.

basic

9,297 4.9 1 min

Other / Tech

Binary / Hex / Decimal Converter

Convert any whole number between binary, octal, decimal, and hexadecimal representations.

basic

9,214 4.1 1 min

Math / Percentage

Matrix Determinant (3×3) Calculator

Compute the determinant of a 3×3 matrix using cofactor expansion along the first row, with a singularity flag.

basic

14,861 4.7 1 min

Physics / Mechanics

Pendulum Period Calculator

Compute the period and frequency of a simple (small-angle) pendulum from its length and the local acceleration due to gr...

basic

19,914 4.2 1 min

Finance / Investing

Gordon Constant-Growth Model Terminal Equity Value Calculator

Calculates stock intrinsic value P = D₁/(k−g) where D₁ is the next dividend, k is required return (CAPM or assumed), and...

basic

14,876 3.9 1 min

Math

McNemar's Test χ² from a Paired 2×2 Table Calculator

Compute McNemar's chi-square statistic for paired-categorical data (e.g. yes/no before vs after a treatment in the same...

basic

18,394 4.3 1 min

Math

2×2 Matrix Multiplication Calculator

Compute the product of two 2×2 matrices A · B element-by-element, returning the four entries of the result matrix.

basic

12,134 4.3 1 min

Math / Geometry

Triangle Circumradius from Sides Calculator

Compute the circumradius R of a triangle from its three side lengths a, b, c: R = abc / (4·area), where area is computed...

basic

23,330 5.0 1 min

Statistics / Descriptive

Kendall's Tau Rank Correlation Calculator

Calculates Kendall's tau τ = (C − D) / (n(n−1)/2), where C is concordant pairs and D is discordant pairs. Robust alterna...

basic

10,962 4.2 1 min

Math / Percentage

Floating-Point Representation Bits and Precision Calculator

Computes the number of significant decimal digits, smallest representable positive number, and largest finite number for...

basic

1,476 4.1 1 min

Statistics / Probability

Exponential Distribution PDF Calculator

Compute the probability density function f(t) = λ · e^(−λt) and the survival function S(t) = e^(−λt) of an exponential d...

basic

5,250 4.6 1 min

Everyday Life / Time & Date

Date Difference Calculator

Count days, weeks, months, or years between any two dates — inclusive or exclusive of weekends.

basic

3,662 4.0 1 min

Showing 433 to 444 of 566 results

explainer Statistics

Standard Deviation in Five Minutes

Standard deviation is "average distance from the average". That one sentence covers 90% of everything you ever need to remember about it.

Daniel Oh

Mar 20, 2026 3 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

Jan 7, 2026 3 min

Reviewed by Daniel Oh

These calculators were technically reviewed by Daniel Oh for accuracy.

Health

Young's Rule Pediatric Dose Calculator

Calculate an age-based pediatric dose from a known adult dose using Young’s Rule. A quick educational tool for students...

basic

22,628 5.0 1 min

Best Free Calculator

Browse categories

Daniel Oh

Cube Volume Calculator

Binary / Hex / Decimal Converter

Matrix Determinant (3×3) Calculator

Pendulum Period Calculator

Gordon Constant-Growth Model Terminal Equity Value Calculator

McNemar's Test χ² from a Paired 2×2 Table Calculator

2×2 Matrix Multiplication Calculator

Triangle Circumradius from Sides Calculator

Kendall's Tau Rank Correlation Calculator

Floating-Point Representation Bits and Precision Calculator

Exponential Distribution PDF Calculator

Date Difference Calculator

Standard Deviation in Five Minutes

Percentages Without the Headache

Reviewed by Daniel Oh

Young's Rule Pediatric Dose Calculator