Calculator Guides & How-To Articles
Expert-written walkthroughs for every calculator on Nexus. Learn the formulas behind each tool, understand your results, and apply them to real-world decisions — whether you're managing finances, tracking health, or solving math problems.
Featured Guides
How to Use the Compound Interest Calculator
A step-by-step walkthrough of compound interest: how the formula works, what inputs to provide, and how to interpret growth projections for savings and investments.
Read guideUnderstanding Loan Amortization: A Step-by-Step Guide
Learn how loan amortization schedules work, how principal vs. interest payments shift over time, and how to use the amortization calculator to plan your repayment.
Read guideHow to Calculate Mortgage Payments Accurately
Understand every component of a mortgage payment — principal, interest, PMI, taxes, and insurance — and learn to use our mortgage calculator for precise estimates.
Read guideHow to Calculate Your BMI and What It Means
A complete guide to Body Mass Index: the standard formula (metric and imperial), what each BMI range means clinically, and the limitations of BMI as a sole health indicator.
Read guideHow to Use the Percentage Calculator for Everyday Problems
Master all three percentage problem types — finding a percentage, finding what percentage one number is of another, and finding a number given a percentage — with real-world examples.
Read guideFinance
Mortgages, loans, investments, and personal finance
How to Use the Compound Interest Calculator
A step-by-step walkthrough of compound interest: how the formula works, what inputs to provide, and how to interpret growth projections for savings and investments.
Read guideUnderstanding Loan Amortization: A Step-by-Step Guide
Learn how loan amortization schedules work, how principal vs. interest payments shift over time, and how to use the amortization calculator to plan your repayment.
Read guideHow to Calculate Mortgage Payments Accurately
Understand every component of a mortgage payment — principal, interest, PMI, taxes, and insurance — and learn to use our mortgage calculator for precise estimates.
Read guideAPR vs. Interest Rate: What Every Borrower Should Know
Understand the crucial difference between APR and nominal interest rate, why lenders advertise both, and how to use our APR calculator to compare loan offers fairly.
Read guideUsing the Investment Calculator for Retirement Planning
A complete guide to projecting long-term portfolio growth using the investment calculator — covering contribution amounts, expected returns, compounding frequency, and inflation adjustment.
Read guideDebt-to-Income Ratio: What It Is and How to Improve It
Learn what debt-to-income ratio (DTI) means for mortgage approval and personal finance health, how lenders evaluate it, and actionable ways to reduce yours using our DTI calculator.
Read guideHealth
BMI, calorie needs, body fat, pregnancy tracking
How to Calculate Your BMI and What It Means
A complete guide to Body Mass Index: the standard formula (metric and imperial), what each BMI range means clinically, and the limitations of BMI as a sole health indicator.
Read guideUnderstanding Calorie Needs: Using the BMR Calculator
Basal Metabolic Rate explained: what it is, the Mifflin-St Jeor and Harris-Benedict formulas, how activity multipliers work, and how to calculate your Total Daily Energy Expenditure (TDEE).
Read guideHow to Track Body Fat Percentage Over Time
Understand body fat percentage measurement methods (Navy Method, skinfold calipers, DEXA), healthy ranges by age and sex, and how to interpret results from our body fat calculator.
Read guideUsing the Pregnancy Calculator: Due Date & Milestones
How due date calculation works using Naegele's Rule and LMP (Last Menstrual Period), what each trimester involves, and how to use our pregnancy calculator to track key milestones.
Read guideMacro Calculator Guide: Protein, Carbs & Fat Explained
A comprehensive guide to calculating and balancing macronutrients for your fitness goal — whether fat loss, muscle gain, or maintenance — using our macro calculator.
Read guideIdeal Weight Ranges by Height and Frame Size
Explore the major ideal body weight formulas (Hamwi, Devine, Robinson, Miller), how frame size factors in, and how to use our ideal weight calculator for a realistic, personalized estimate.
Read guideMath & Science
Percentages, statistics, unit conversions, and more
How to Use the Percentage Calculator for Everyday Problems
Master all three percentage problem types — finding a percentage, finding what percentage one number is of another, and finding a number given a percentage — with real-world examples.
Read guideUnderstanding Standard Deviation with Examples
A clear explanation of standard deviation and variance: the difference between population and sample formulas, what σ tells you about data spread, and how to read output from our statistics calculator.
Read guideHow to Convert Units: A Complete Conversion Guide
A comprehensive reference for converting length, weight, volume, temperature, speed, and area units between metric and imperial systems using our conversion calculator.
Read guideScientific Notation Made Simple: Format & Calculate
Learn how to read and write numbers in scientific notation, perform arithmetic operations (×, ÷, +, −), convert between standard and scientific form, and avoid common mistakes.
Read guideHow the Half-Life Calculator Works (Radioactive Decay)
A complete guide to radioactive half-life: the exponential decay formula, how to find remaining quantity or elapsed time, real-world examples in nuclear medicine and archaeology.
Read guideTriangle Calculator Guide: Sides, Angles & Area
A thorough reference for solving any triangle — right, acute, or obtuse — using trigonometric laws (Law of Sines, Law of Cosines), the Pythagorean theorem, and Heron's formula for area.
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