Every calculator
you'll ever need,
in one nest.
Free, lightning-fast calculators for finance, health, education, math and everyday life. Built with real formulas. Zero signup. Beautifully designed.
Categories
Pick a category to explore tools built for it.
Finance Calculators
Loans, mortgages, taxes and investments — make smarter money decisions.
Health Calculators
BMI, calories, body fat and hydration — track your wellness.
Education Calculators
GPA, grades and study planning for students.
Math Calculators
Percentages, fractions, averages and more.
Lifestyle Calculators
Everyday tools to simplify daily decisions.
Time & Date Tools
Age, date difference, countdown timers.
Popular Calculators
Loan Calculator
Estimate monthly loan payments, total interest and amortization.
BMI Calculator
Calculate your Body Mass Index in metric or imperial units.
Percentage Calculator
Find percentages, percent of, and percent change.
Age Calculator
Calculate exact age in years, months, days.
Mortgage Calculator
Estimate your mortgage payment including taxes and insurance.
Calorie Calculator
Estimate your daily calorie needs (TDEE) with the Mifflin-St Jeor equation.
Trending Tools
Tip Calculator
Calculate tip and split the bill between any number of people.
Paycheck Calculator (US)
Estimate US take-home pay after federal, FICA and state taxes.
Pregnancy Due Date Calculator
Estimate your due date and current week of pregnancy from your last period.
Investment Calculator
Project the future value of investments with regular contributions.
Latest Articles
In-depth guides on the math behind the calculators.
Daily Calorie Needs: TDEE, BMR and Macros, Explained Without the Mystery
BMR, TDEE, activity multipliers, macros — the calorie ecosystem isn't complicated once you see how the four numbers connect. Here's the full picture.
How to Calculate a Percentage: 6 Common Cases With Real Examples
Percentages show up in tips, taxes, discounts, exam scores, and quarterly reports. Here's a single framework that solves every common case in under 10 seconds.
Mortgage Affordability: How Much House Can You Actually Afford?
Banks will lend you more than you should borrow. The real affordability number sits at the intersection of three ratios — and your honest monthly budget.
What our users say
Join 50,000+ people who rely on CalcNest every month.
"I use the mortgage and investment calculators daily for client reports. The formulas are spot-on and the UI is incredibly clean."
"The BMI and calorie calculators are precise and patient-friendly. I recommend CalcNest to everyone in my practice."
"GPA calculator saved me during finals week. No signup, instant results, and it just works every single time."
"Fast, beautiful, and completely free. The percentage and discount tools are now part of my invoicing workflow."
"Body fat and water intake calculators help me create personalized plans. My clients love how easy it is to use."
"Tax and salary calculators made my quarterly budgeting so much easier. Highly recommend for any entrepreneur."
Calculators built for clarity, designed for speed.
CalcNest brings together the most-used online calculators in one beautifully fast site. From mortgage payments and BMI to GPA and percentages, every tool is built with real formulas, clear explanations and instant results — no signup, no fluff.
- · Real formulas with step-by-step breakdowns
- · Mobile-first responsive design
- · Instant results with copy & share
- · Optimized for Core Web Vitals
Why CalcNest?
Frequently Asked Questions
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