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

Health

CHA₂DS₂-VASc Atrial Fibrillation Stroke Risk Calculator

Calculates the CHA₂DS₂-VASc score from CHF, hypertension, age ≥75, diabetes, stroke/TIA (×2), vascular disease, age 65–7...

basic

20,131 4.9 1 min

Physics

CPU Instruction Execution Time from CPI and Clock Rate Calculator

Calculates CPU execution time = (instruction count × CPI) / clock_frequency, and MIPS = clock_frequency / (CPI × 10⁶).

basic

21,363 4.4 1 min

Math

One-Sample Z-Test Statistic Calculator

Compute the one-sample z-test statistic for a population mean when σ is known: z = (x̄ − μ₀) / (σ / √n). Compare to ±1.9...

basic

329 4.9 1 min

Math / Percentage

Linear Equation Solver

Solve a single linear equation of the form ax + b = c for the unknown x, including a clear "no solution / infinite solut...

basic

11,368 4.3 1 min

Math

Standard Error of a Proportion Calculator

Compute the standard error of a sample proportion from successes and trials: p̂ = x/n, SE = √(p̂(1−p̂)/n). Also reports...

basic

8,949 4.0 1 min

Everyday Life / Tips

Typing Speed Calculator

Compute typing speed in words per minute (WPM) from total words typed and the time taken, with adjustment for accuracy.

basic

16,915 4.2 1 min

Math

Multinomial Coefficient from Three Counts Calculator

Compute the multinomial coefficient C(n; k₁, k₂, k₃) = n! / (k₁! · k₂! · k₃!), where n = k₁ + k₂ + k₃. This counts the d...

basic

2,785 4.0 1 min

Statistics

Sample Excess Kurtosis of 5 Numbers Calculator

Compute the adjusted excess kurtosis g₂ of a 5-number list (zero for a normal distribution; positive = heavier tails / m...

basic

22,134 4.0 1 min

Other / Tech

IPv4 Subnet Calculator

Enter a CIDR notation IPv4 address and get the network address, broadcast address, usable host range, subnet mask, and h...

basic

12,119 4.1 1 min

Math / Geometry

Regular Polygon Perimeter Calculator

Compute the perimeter, apothem, and area of a regular polygon from its number of sides and side length.

basic

18,975 4.1 1 min

Physics / Mechanics

Thermal Expansion Calculator

Compute the linear thermal expansion of a solid from its original length, temperature change, and the material's linear...

basic

16,925 4.2 1 min

Physics

Pulley Mechanical Advantage & Load Calculator

Calculates mechanical advantage, required effort force, and rope travel distance for a compound pulley system to lift a...

basic

1,214 3.9 1 min

Showing 181 to 192 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

CHA₂DS₂-VASc Atrial Fibrillation Stroke Risk Calculator

CPU Instruction Execution Time from CPI and Clock Rate Calculator

One-Sample Z-Test Statistic Calculator

Linear Equation Solver

Standard Error of a Proportion Calculator

Typing Speed Calculator

Multinomial Coefficient from Three Counts Calculator

Sample Excess Kurtosis of 5 Numbers Calculator

IPv4 Subnet Calculator

Regular Polygon Perimeter Calculator

Thermal Expansion Calculator

Pulley Mechanical Advantage & Load Calculator

Percentages Without the Headache

Standard Deviation in Five Minutes