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 / Solutions

Boiling Point Elevation Calculator

Compute the boiling-point elevation of a solution from molality, the solvent's ebullioscopic constant, and the van't Hof...

basic

1,537 4.3 1 min

Physics / Mechanics

Force Calculator

Solve F = ma for any of force, mass, or acceleration — with unit-aware defaults.

basic

5,996 4.6 1 min

Math / Geometry

Distance Between Two 3D Points

Compute the Euclidean distance between two points in 3D space, given their (x, y, z) coordinates.

basic

4,248 5.0 1 min

Physics

Compressible Flow Mach Number from Velocity Calculator

Calculates the Mach number for compressible gas flow from flow velocity, specific heat ratio γ, gas constant R, and stat...

basic

10,207 3.9 1 min

Math

Sample Size for a Proportion Calculator

Compute the minimum sample size required to estimate a proportion within a target margin of error E at a chosen confiden...

basic

13,177 4.9 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

10,715 4.0 1 min

Statistics

F-Test Variance Ratio Calculator

Compute the F-statistic for comparing two sample variances (the larger over the smaller) and report the numerator and de...

basic

3,628 4.0 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

5,973 4.6 1 min

Physics

Moody Chart Friction Factor from Reynolds Number and Roughness Calculator

Approximates the Darcy–Weisbach friction factor using the Colebrook–White equation (Churchill approximation): 1/√f = −2·...

basic

3,184 4.9 1 min

Math

Sample Excess Kurtosis from 4th Moment and Variance Calculator

Compute the excess kurtosis of a distribution from its centred fourth moment m₄ = E[(X − μ)⁴] and the variance σ²: exces...

basic

14,086 4.1 1 min

Statistics / Descriptive

Regression Slope and Intercept from Sums Calculator

Computes the OLS regression slope b₁ = [nΣXY − ΣXΣY] / [nΣX² − (ΣX)²] and intercept b₀ = (ΣY − b₁ΣX) / n from five summa...

basic

15,853 4.0 1 min

Statistics / Probability

Expected Value of 5 Outcomes Calculator

Compute the expected value of a discrete random variable defined by up to five (probability, payoff) pairs. Reports E[X]...

basic

8,684 4.7 1 min

Showing 145 to 156 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

Boiling Point Elevation Calculator

Force Calculator

Distance Between Two 3D Points

Compressible Flow Mach Number from Velocity Calculator

Sample Size for a Proportion Calculator

Angular (Rotational) Kinetic Energy Calculator

F-Test Variance Ratio Calculator

Linear Equation Solver

Moody Chart Friction Factor from Reynolds Number and Roughness Calculator

Sample Excess Kurtosis from 4th Moment and Variance Calculator

Regression Slope and Intercept from Sums Calculator

Expected Value of 5 Outcomes Calculator

Standard Deviation in Five Minutes

Percentages Without the Headache

Reviewed by Daniel Oh

Young's Rule Pediatric Dose Calculator