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

Statistics / Probability

Lottery Odds Calculator

Compute the odds of winning a "pick k from n" lottery (e.g. 6/49) — the probability of matching all k drawn numbers, exp...

basic

19,395 4.0 1 min

Math

Trapezoidal Rule Definite Integral Calculator

Approximates a definite integral using the composite trapezoidal rule from up to five equally-spaced function values.

basic

17,618 3.9 1 min

Physics / Mechanics

Angular (Rotational) Kinetic Energy Calculator

Calculates the rotational kinetic energy of a rigid body from its moment of inertia and angular velocity, plus equivalen...

basic

5,772 3.9 1 min

Statistics

Welch's Two-Sample t-Test Calculator

Compute the Welch (unequal-variances) two-sample t statistic and its Welch-Satterthwaite degrees of freedom from the two...

basic

23,425 3.9 1 min

Biology / Human Body

Blood Alcohol Content Calculator

Estimate blood alcohol content using the Widmark formula from drinks consumed, body weight, sex, and time elapsed.

basic

19,453 4.7 1 min

Physics / Mechanics

Escape Velocity from Planet Surface Calculator

Calculates escape velocity v_esc = √(2GM/R) and the corresponding kinetic energy needed per kg of payload. For Earth: M...

basic

2,256 3.9 1 min

Math

Newton-Raphson One-Iteration Update Calculator

Apply a single iteration of Newton's method (Newton-Raphson) given the current estimate x_n, the function value f(x_n),...

basic

22,521 3.9 1 min

Other / Games

Chess Elo Expected Score Calculator

Compute the expected score (probability of winning) for player A against player B from their Elo ratings using E_A = 1 /...

basic

6,529 4.1 1 min

Math / Geometry

Parallelogram Area Calculator

Compute the area of a parallelogram from a base and the perpendicular height to that base.

basic

13,613 5.0 1 min

Math

Euler Perfect Number Formula from Mersenne Exponent Calculator

Computes an even perfect number using Euler's theorem: N = 2^(p−1) × M_p where M_p = 2^p − 1 is the Mersenne number. Kno...

basic

4,597 4.2 1 min

Sports / Running

Race Finish Time Prediction from Reference Race (Riegel Formula) Calculator

Predicts finish time for a target race distance from a known race result: t₂ = t₁ × (d₂/d₁)^1.06. Commonly used to predi...

basic

13,215 4.1 1 min

Everyday Life

Wallpaper Rolls Needed for a Room Calculator

Estimates how many wallpaper rolls are needed to cover four walls, accounting for doors and windows: strips per roll = f...

basic

18,557 3.8 1 min

Showing 529 to 540 of 545 results

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 16, 2026 3 min

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

Dec 6, 2025 3 min

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Browse categories

Daniel Oh

Lottery Odds Calculator

Trapezoidal Rule Definite Integral Calculator

Angular (Rotational) Kinetic Energy Calculator

Welch's Two-Sample t-Test Calculator

Blood Alcohol Content Calculator

Escape Velocity from Planet Surface Calculator

Newton-Raphson One-Iteration Update Calculator

Chess Elo Expected Score Calculator

Parallelogram Area Calculator

Euler Perfect Number Formula from Mersenne Exponent Calculator

Race Finish Time Prediction from Reference Race (Riegel Formula) Calculator

Wallpaper Rolls Needed for a Room Calculator

Percentages Without the Headache

Standard Deviation in Five Minutes