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

Chemistry / Reactions

Half-Life Calculator

Compute the remaining quantity of a decaying substance after any number of half-lives.

basic

1,008 5.0 1 min

Statistics / Probability

Minimum Detectable Effect from Sample Size and Alpha Calculator

Calculates the minimum detectable effect MDE = (z_α + z_β) × √(2σ²/n), where z_α is the critical value and z_β correspon...

basic

18,219 4.1 1 min

Math

Harmonic Progression n-th Term Calculator

Compute the n-th term of a harmonic progression — a sequence whose reciprocals form an arithmetic progression with first...

basic

12,562 4.2 1 min

Math / Percentage

Mean Absolute Deviation Calculator

Compute the mean absolute deviation (MAD) — the average absolute distance of each value from the mean — alongside the me...

basic

16,274 4.1 1 min

Chemistry / Solutions

Mole Calculator

Convert between mass, number of moles, and molar mass for any substance.

basic

11,185 4.6 1 min

Math

Cohen's h Effect Size Between Two Proportions Calculator

Compute Cohen's h, the standardised effect-size between two proportions. h = 2·arcsin(√p₁) − 2·arcsin(√p₂). Interpretati...

basic

6,794 4.2 1 min

Everyday Life / Tips

Party Cost Calculator

Estimate the total cost and per-guest cost of a party, given fixed costs (venue, decor) and per-guest costs (food, drink...

basic

20,202 4.0 1 min

Physics

Thin-Lens Magnification from Object and Image Distance Calculator

Compute the lateral magnification of a thin converging or diverging lens: m = −dᵢ/dₒ, where dₒ is the object distance an...

basic

4,148 4.4 1 min

Math / Geometry

Circle Circumference Calculator

Get the circumference, diameter, and area of a circle from any one of its radius, diameter, area, or circumference.

basic

10,018 4.0 1 min

Physics / Mechanics

Hooke's Law Calculator

Compute the spring force, potential energy stored, and displacement using Hooke's law.

basic

21,918 4.7 1 min

Math / Percentage

Hash Table Load Factor and Collision Probability Calculator

Calculates the load factor λ = n/m (items/buckets), the approximate collision probability per insertion (birthday proble...

basic

16,769 3.8 1 min

Ecology / Energy

Solar Panel Calculator

Estimate the solar panel system size needed to cover your monthly electricity usage given local sun hours and system eff...

basic

24,023 4.6 1 min

Showing 361 to 372 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

Calcify

Browse categories

Daniel Oh

Half-Life Calculator

Minimum Detectable Effect from Sample Size and Alpha Calculator

Harmonic Progression n-th Term Calculator

Mean Absolute Deviation Calculator

Mole Calculator

Cohen's h Effect Size Between Two Proportions Calculator

Party Cost Calculator

Thin-Lens Magnification from Object and Image Distance Calculator

Circle Circumference Calculator

Hooke's Law Calculator

Hash Table Load Factor and Collision Probability Calculator

Solar Panel Calculator

Percentages Without the Headache

Standard Deviation in Five Minutes