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Why CalcTray?

CalcTray is a free collection of calculators for personal finance, math, health, science, and everyday use. Tools cover mortgage payoff, compound interest, tip splitting, unit conversions, and more.

Every calculator runs in your browser. Your data stays on your device. No account, no download, no paywall.

All calculators support shareable URLs. Copy the address bar to send your exact inputs to anyone.

Financial Calculators

The Mortgage Payoff Calculator shows how much interest and time you save by making extra monthly payments. Enter your loan details and see your new payoff date alongside the original schedule. For many homeowners, even an extra $100–$200 per month can shave years off a 30-year mortgage and save tens of thousands in interest. The Compound Interest Calculator illustrates investment growth across four compounding frequencies: monthly, quarterly, semi-annually, and annually. Add regular monthly contributions and see a year-by-year breakdown of how your balance grows over time. The Loan Payment Calculator generates a full amortization schedule for any fixed-rate loan, including auto loans, personal loans, and mortgages. Each monthly payment is broken down into its principal and interest portions so you can see exactly how your balance decreases over time. The Savings Goal Calculator works back from your target: enter your goal amount, current savings, expected interest rate, and timeline. The calculator tells you the exact monthly deposit needed to reach your goal on schedule, along with a month-by-month projection.

Everyday Calculators

The Tip Calculator & Bill Splitter handles any size group. Choose from preset tip percentages (15%, 18%, 20%, 25%) or enter a custom amount, then divide the total evenly across any number of people. Every result shows both the group totals and the per-person breakdown. The Percentage Calculator solves three types of percentage problems in one place: finding a percentage of a number, determining what percent one value is of another, and calculating the percentage change between two numbers. Switch between modes using the tabs. The Weighted Grade Calculator turns each category's grade and weight (homework, exams, finals) into an overall percentage and a US letter grade, and auto-normalizes when the weights don't add up to 100%.

Health Calculators

The BMI Calculator computes your Body Mass Index from height and weight, supporting both imperial and metric units. Results include your BMI value, weight category, and a visual chart showing where you fall on the BMI scale. The BMR Calculator estimates your Basal Metabolic Rate (the number of calories your body burns at rest) using the Mifflin-St Jeor equation. Results include daily calorie needs for different activity levels to help you plan your nutrition.

Science Calculators

The Ohm's Law Calculator solves for voltage, current, resistance, or power given any two known values. Enter what you know and the calculator determines the rest, with clear formula explanations for each relationship. The Bernoulli's Equation Calculator applies the conservation of energy principle to fluid flow, calculating pressure, velocity, and elevation changes between two points in a fluid system.

Math Calculators

Solve geometry and math problems with CalcTray's free math calculators. Calculate areas, volumes, slopes, and more for rectangles, triangles, circles, spheres, cylinders, and other shapes.

Unit Converters

Convert between units instantly with CalcTray's free unit converters. Length, weight, temperature, volume, and area conversions with all common units supported.