Blog
Guides and explainers on the maths people actually search for - percentages, logarithms, trigonometry, statistics, exponents and more - with the working shown so you can follow the method, not just copy the answer.
Gambler's Fallacy: Why Probability Intuition Fails
Five heads in a row does not make tails due. What the gambler's fallacy is, why the birthday paradox surprises everyone, and how real lottery odds compare.
Understanding Time Zones: UTC Offsets & World Time Math
Guide to time zone math: Coordinated Universal Time (UTC), positive and negative offsets, daylight saving shifts, and international date lines.
Mastering Percentage Calculations: Formulas & Practical Tips
Complete guide to percentage math: calculate percentages of numbers, percentage increases and decreases, markups, margins, and reverse percentages.
PayPal Fee Breakdown: Merchant Rates & Payout Formulas
Understand PayPal transaction fees: standard 2.99% + $0.49 formulas, international fees, invoice fees, and how to calculate reverse fee pricing.
How to Use an Online Calculator: Shortcuts, Rules & Memory
Master online calculators: keyboard shortcuts, operator precedence (PEMDAS/BODMAS), and memory keys (M+, M-, MR, MC) for rapid daily calculations.
Simple vs. Compound Interest: Formulas & Growth Schedules
Learn the math of simple and compound interest: APR vs APY, compounding frequencies, the Rule of 72, and investment growth schedules.
How to Calculate GPA: Weighted & Unweighted Scale Math
Step-by-step guide to calculating GPA: unweighted 4.0 scales, weighted AP/Honors 5.0 scales, credit-hour weighting, and cumulative GPA math.
How Currency Exchange Rates Work: Spreads & FX Math
Learn how foreign exchange rates work: base and quote currencies, bid-ask spreads, mid-market rates, cross rates, and conversion math.
BMI Calculator & Body Mass Index: Formulas & Health Ranges
Understand Body Mass Index: metric and imperial formulas, WHO weight categories, prime index calculations, and complementary body composition metrics.
The Mathematics of Age: Leap Years & Date Calculations
How exact age is calculated: Gregorian calendar math, leap year rules, day counts, timezone offsets, and converting age into hours, days, and weeks.
Client-Side Web Tools: Architecture, Speed & Privacy
How modern web standards like Web Workers, the Web Crypto API, Canvas, and pure JS run developer utilities locally without server data uploads.
Guide to Data Encoding, Escaping & Cryptographic Hashing
Deep dive into URL percent-encoding, Base64 representation, HTML escaping against XSS, and one-way cryptographic hashing algorithms.
Everyday Math: Formulas Behind BMI, Compound Interest & GPA
Step-by-step mathematical breakdown of Body Mass Index, compound interest accumulation equations, GPA calculations, and percentage shifts.
Unit Conversion Made Simple: Length, Weight and Temperature
A practical guide to converting between metric and imperial units for length, weight and temperature, with quick reference tables.
Ratios Explained: Simplify, Compare and Convert with Confidence
What ratios are, how to simplify them using GCD, how to find equivalent ratios, and when to use ratios vs fractions.
Binary, Octal and Hexadecimal: Understanding Number Bases
How the decimal, binary, octal and hexadecimal number systems work, why computers use binary, and how to convert between them.
Compound Interest Explained: How Your Money Grows Over Time
Understand compound interest, the rule of 72, and how regular contributions accelerate investment growth with real calculations.
Daily Calorie Needs: How to Calculate BMR and TDEE
Estimate your daily calorie needs using the Harris-Benedict equation, understand BMR vs TDEE, and learn how activity level affects your target.
BMI Explained: How to Calculate and Interpret Your Body Mass Index
Learn how to calculate BMI from weight and height, understand the categories, and know when BMI doesn't tell the full story.
Mean, Median, Mode and Range: When to Use Each Average
The three types of averages explained with worked examples, plus how range and spread help you understand your data.
What Is a Logarithm? A Plain-English Beginner's Guide
What logarithms are, how to read them, and how base-10 versus natural logarithms differ, with worked examples you can check on any calculator.
Trigonometry Guide: Sine, Cosine and Tangent Explained
Sine, cosine, and tangent explained through the unit circle and right triangles with SOH-CAH-TOA, exact values, inverse functions, and degrees versus radians.
Statistics Basics: Mean, Median, Mode, Range, Variance and Standard Deviation
Mean, median, mode, range, variance, and standard deviation explained with worked examples on small data sets, plus how to tell population from sample.
Square and Cube Roots Explained: How to Find, Use, and Compute Them
What square and cube roots are, how to compute them on a calculator, why some are irrational, and how they relate to fractional powers, with worked examples.
Significant Figures Guide: How to Count, Round, and Use Them
What significant figures are, how to count and round them to a chosen number, and which rules apply when you multiply and divide versus add and subtract.
Scientific Notation: What It Is and How to Convert It
What scientific notation is, how to convert numbers to and from standard form, why scientists use it, and how it ties into significant figures, with examples.
Probability, Permutations and Combinations: nPr and nCr Explained
Basic probability, permutations (nPr) when order matters, and combinations (nCr) when it does not, with worked examples for each on a calculator.
Pi Explained: What π Is and How to Use It
What pi means as the ratio of circumference to diameter, why its decimal never ends, and the formulas where it does real work on a calculator.
Percentages Explained: How to Calculate Them Correctly
How to calculate percentages every time: finding X% of Y, working out X as a percent of Y, increases and decreases, and conversions, with real examples.
Percentage Change: How to Calculate Increase and Decrease
How to work out percentage increase and decrease with the formula (new minus original) divided by original times 100, and worked examples to follow.
Order of Operations: Why 12 + 7 × 3 Is 33
PEMDAS and BODMAS explained, plus the exact precedence rules this calculator applies, including exponents, percent, and implicit multiplication.
The Natural Logarithm: What ln Means and How to Use It
What ln and the number e mean, why ln(1) equals 0 and ln(e) equals 1, and how natural logs describe growth, decay, and doubling time.
Log and Exponent Rules Explained
The product, quotient, and power rules for logarithms, paired with the matching exponent laws, plus a cheat sheet and worked examples.
How to Use a Scientific Calculator: Buttons, Functions, and Worked Examples
Step-by-step guide to using a scientific calculator: arithmetic, %, powers, roots, trig, logs, memory keys, DEG vs RAD, and SCI mode, with worked examples.
Fractions Guide: Numerators, Denominators, and How to Add, Multiply, and Divide Them
How to add, subtract, multiply, and divide fractions, when you need a common denominator, and how to convert between fractions, decimals, and percents.
Why 0.1 + 0.2 Is 0.30000000000000004
Why binary floating point makes 0.1 plus 0.2 come out as 0.30000000000000004, and how this calculator rounds it back to a clean 0.3.
Factorials Explained: What n! Means and Where It Shows Up
What a factorial is, why 0! = 1, how to type n! on the calculator, a table of factorial values, and where factorials show up in probability and counting.
Exponents Explained: What Powers Mean and How to Use Them
What exponents and powers mean, with the rules for multiplying, dividing, zero, negative, and fractional powers, plus worked examples for any calculator.
Degrees vs Radians: The Difference and How to Convert
What degrees and radians measure, why radians exist, how to convert between the two units, and what the DEG/RAD toggle changes when you type sin(30).
Calculator Memory Functions: MC, MR, MS, M+, and M- Explained
What the memory keys on a scientific calculator do: how MC, MR, MS, M+, and M- store, recall, and add to a saved value during multi-step calculations.
Calculator Keyboard Shortcuts: Type Faster Than You Click
The keyboard shortcuts for The Scientific Calculator: Enter to evaluate, Escape to clear, operator substitutions, the power key, and normal text editing.
Written and verified by Akash Pandey. Every number you see here can be reproduced on the main calculator.