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

Physics

Ideal Gas Internal Energy Change and Heat Capacity Calculator

Calculates the change in internal energy ΔU = n·Cv·ΔT and enthalpy change ΔH = n·Cp·ΔT for an ideal monatomic (Cv = 3R/2...

basic

11,072 4.8 1 min

Physics

LMTD Log Mean Temperature Difference Calculator

Calculates the Log Mean Temperature Difference (LMTD) for counterflow or parallel-flow heat exchangers from terminal tem...

basic

14,635 4.6 1 min

Finance

Price-to-Earnings (P/E) Ratio from Stock Price and EPS Calculator

Compute the P/E ratio of a stock from its current price and trailing (or forward) EPS: P/E = price / EPS. Also reports t...

basic

17,479 4.0 1 min

Math / Geometry

Circumcircle of a Triangle from Three Vertices Calculator

Compute the circumcircle of a triangle given the (x, y) coordinates of its three vertices. Reports the side lengths a, b...

basic

20,279 4.8 1 min

Math / Percentage

Average Rate of Change Calculator

Compute the average rate of change (slope of the secant line) of a function f from a to b: (f(b) − f(a)) / (b − a).

basic

18,944 4.1 1 min

Physics

Solar Panel Daily Energy Output Calculator

Estimates daily and monthly energy output from a solar panel array from rated power, peak sun hours, and system efficien...

basic

18,947 4.2 1 min

Math / Geometry

Regular Polygon Area Calculator

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

basic

11,428 4.8 1 min

Math / Geometry

Ellipse Calculator

Compute the exact area and Ramanujan-approximated perimeter of an ellipse from the lengths of its semi-major and semi-mi...

basic

16,492 4.8 1 min

Statistics / Probability

Sample Size Calculator

Work out how many respondents you need for a given confidence level, margin of error, and population size.

basic

3,504 4.2 1 min

Math

Logarithm Change-of-Base Calculator

Compute the logarithm of x with respect to an arbitrary base b using the change-of-base identity log_b(x) = ln(x) / ln(b...

basic

14,004 4.1 1 min

Health

Framingham 10-Year CVD Risk Calculator

Estimates 10-year cardiovascular disease risk using a simplified Framingham point score from age, cholesterol, blood pre...

basic

1,728 4.6 1 min

Math / Percentage

Depressed Cubic (Cardano's Method) Real Root Calculator

Finds the real cube root of the depressed cubic x³ + px + q = 0 using Cardano's formula: x = ∛(−q/2 + √D) + ∛(−q/2 − √D)...

basic

756 4.2 1 min

Showing 505 to 516 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

Ideal Gas Internal Energy Change and Heat Capacity Calculator

LMTD Log Mean Temperature Difference Calculator

Price-to-Earnings (P/E) Ratio from Stock Price and EPS Calculator

Circumcircle of a Triangle from Three Vertices Calculator

Average Rate of Change Calculator

Solar Panel Daily Energy Output Calculator

Regular Polygon Area Calculator

Ellipse Calculator

Sample Size Calculator

Logarithm Change-of-Base Calculator

Framingham 10-Year CVD Risk Calculator

Depressed Cubic (Cardano's Method) Real Root Calculator

Percentages Without the Headache

Standard Deviation in Five Minutes