# Calculas (calculas.co)
> A modern, free, multi-purpose online calculation platform featuring verified formulas, step-by-step mathematical proofs, interactive charts, and downloadable reports.

## Overview
- **Domain:** https://calculas.co
- **Supported Languages:** English (en), Spanish (es), Turkish (tr)
- **Supported Currencies:** USD ($), EUR (€), TRY (₺), GBP (£)
- **Primary Capabilities:** Financial amortization, tax computation, mathematical analysis, health metrics, scientific conversions, date-time calculations, and business analytics.

## Available Calculation Suites

### Finance (17 Calculators)
Calculators for mortgages, loans, investments, taxes, and personal wealth.

- [Mortgage Calculator](https://calculas.co/finance/mortgage-calculator): Estimate monthly home loan payments, interest, and payoff timeline.
- [Compound Interest Calculator](https://calculas.co/finance/compound-interest-calculator): Calculate future wealth accumulation with annual or monthly compounding.
- [Loan Calculator](https://calculas.co/finance/loan-calculator): Estimate monthly payments and total interest for personal or auto loans.
- [Investment & ROI Calculator](https://calculas.co/finance/investment-calculator): Calculate total ROI, annualized return, and capital gain.
- [ROI Calculator (Return on Investment)](https://calculas.co/finance/roi-calculator): Calculate overall and annualized Return on Investment (ROI).
- [Salary & Hourly Wage Converter](https://calculas.co/finance/salary-calculator): Convert between annual salary, monthly pay, and hourly rates.
- [Simple Interest Calculator](https://calculas.co/finance/simple-interest-calculator): Calculate basic interest on loans or deposits without compounding.
- [CAGR Calculator (Compound Annual Growth Rate)](https://calculas.co/finance/cagr-calculator): Calculate Compound Annual Growth Rate across multiple periods.
- [Loan Payoff & Extra Payments Calculator](https://calculas.co/finance/loan-payoff-calculator): Calculate interest savings and earlier payoff dates with extra payments.
- [Savings Goal Calculator](https://calculas.co/finance/savings-calculator): Calculate required monthly savings to achieve your financial goal.
- [Debt-to-Income (DTI) Ratio Calculator](https://calculas.co/finance/debt-to-income-calculator): Calculate front-end and back-end Debt-to-Income (DTI) ratios for mortgage readiness.
- [Income Tax & Effective Rate Calculator](https://calculas.co/finance/income-tax-calculator): Estimate progressive federal taxes, effective tax rate, and take-home pay.
- [Rental Property ROI & Wealth Projection](https://calculas.co/finance/rental-property-roi): Analyze rental cash flow, cap rate, cash-on-cash return, and 10-year wealth projection.
- [Calculadora Cuota Autónomos e IRPF España](https://calculas.co/finance/cuota-autonomo-calculadora): Calcula la cuota RETA por ingresos reales, IRPF y beneficio neto en España.
- [Calculadora Sueldo Neto España (IRPF y SS)](https://calculas.co/finance/sueldo-neto-espana): Convierte tu salario bruto a sueldo neto mensual en España con IRPF y Seguridad Social.
- [Brütten Nete Maaş Hesaplama (SGK ve Vergi)](https://calculas.co/finance/brutten-nete-maas-hesaplama): Aylık brüt maaştan SGK, gelir vergisi ve damga vergisi düşerek net maaşı hesaplayın.
- [Kıdem ve İhbar Tazminatı Hesaplama](https://calculas.co/finance/kidem-ihbar-tazminati-hesaplama): Hizmet süresi ve brüt maaş üzerinden kıdem ve ihbar tazminatı hesaplama aracı.

### Math (10 Calculators)
Calculators for percentages, fractions, algebra, statistics, and scientific math.

- [Percentage Calculator](https://calculas.co/math/percentage-calculator): Solve any percentage problem: X% of Y, percentage difference, discount & tax.
- [Fraction Calculator](https://calculas.co/math/fraction-calculator): Add, subtract, multiply, and divide fractions with step-by-step simplification.
- [Average, Mean, Median & Mode Calculator](https://calculas.co/math/average-calculator): Calculate mean, median, mode, range, and standard deviation.
- [Ratio Calculator & Simplifier](https://calculas.co/math/ratio-calculator): Solve ratios (A:B = C:D) and scale aspect ratios.
- [GCD & LCM Calculator](https://calculas.co/math/gcd-lcm-calculator): Find Greatest Common Divisor and Least Common Multiple.
- [LCM Calculator (Least Common Multiple)](https://calculas.co/math/lcm-calculator): Calculate the Least Common Multiple (LCM) of integers.
- [Exponent Calculator (Power & Roots)](https://calculas.co/math/exponent-calculator): Calculate base raised to the power of an exponent and roots.
- [Geometry Calculator (Area, Perimeter & Volume)](https://calculas.co/math/geometry-calculator): Calculate area, perimeter, and volume for geometric shapes.
- [Quadratic Equation Calculator](https://calculas.co/math/quadratic-calculator): Solve ax² + bx + c = 0 for roots, discriminant, and vertex.
- [Scientific Math & Exponents Calculator](https://calculas.co/math/scientific-math-calculator): Calculate exponents, roots, logarithms, factorials, and trig functions.

### Health & Fitness (8 Calculators)
Tools for BMI, body fat, caloric requirements, TDEE, and fitness pacing.

- [BMI Calculator](https://calculas.co/health/bmi-calculator): Calculate Body Mass Index based on height, weight, and WHO categories.
- [Basal Metabolic Rate (BMR) Multi-Formula Calculator](https://calculas.co/health/bmr-calculator): Calculate BMR resting energy expenditure with Mifflin-St Jeor & Harris-Benedict.
- [TDEE Calculator (Total Daily Energy Expenditure)](https://calculas.co/health/tdee-calculator): Calculate your maintenance calories based on activity level.
- [Calorie & TDEE Calculator](https://calculas.co/health/calorie-calculator): Calculate daily calorie burn (TDEE) and target calories for weight goals.
- [Body Fat Percentage (U.S. Navy Method)](https://calculas.co/health/body-fat-calculator): Calculate body fat percentage and lean muscle mass using circumference measurements.
- [Ideal Body Weight (IBW) Calculator](https://calculas.co/health/ideal-weight-calculator): Calculate ideal body weight using clinical medical formulas.
- [Daily Protein & Macronutrient Calculator](https://calculas.co/health/protein-calculator): Calculate daily protein requirements for muscle growth or fat loss.
- [Running & Fitness Pace Calculator](https://calculas.co/health/pace-calculator): Calculate running pace (min/km, min/mile) and race split times.

### Unit Converters (8 Calculators)
Convert length, weight, temperature, volume, data storage, speed, and energy.

- [Length Converter](https://calculas.co/converters/length-converter): Convert between metric and imperial distance and length units.
- [Weight & Mass Converter](https://calculas.co/converters/weight-converter): Convert between kg, grams, pounds, ounces, and stone.
- [Temperature Converter](https://calculas.co/converters/temperature-converter): Convert between Celsius (°C), Fahrenheit (°F), and Kelvin (K).
- [Area & Land Converter](https://calculas.co/converters/area-converter): Convert between sq ft, sq meters, acres, and hectares.
- [Speed & Velocity Converter](https://calculas.co/converters/speed-converter): Convert between mph, km/h, m/s, knots, and Mach.
- [Volume & Liquid Capacity Converter](https://calculas.co/converters/volume-converter): Convert between liters, gallons, cups, fluid ounces, and cubic meters.
- [Digital Data Storage & File Size Converter](https://calculas.co/converters/data-storage-converter): Convert between KB, MB, GB, TB, and binary units (KiB, MiB, GiB).
- [Energy & Work Converter](https://calculas.co/converters/energy-converter): Convert between Joules, Calories, kWh, and BTU.

### Date & Time (7 Calculators)
Calculate exact ages, date intervals, business days, time zones, and milestones.

- [Age Calculator](https://calculas.co/date-time/age-calculator): Find exact age, days lived, and countdown to next birthday.
- [Date Difference Calculator](https://calculas.co/date-time/date-difference-calculator): Calculate days, weeks, months, and business days between two dates.
- [Time Difference Calculator (Duration Between Times)](https://calculas.co/date-time/time-difference-calculator): Calculate hours and minutes duration between two times.
- [Business Days Calculator (Working Days)](https://calculas.co/date-time/business-days-calculator): Calculate business/working days between two calendar dates.
- [Event & Milestone Countdown Calculator](https://calculas.co/date-time/countdown-calculator): Countdown days, hours, and minutes until any future event.
- [Day of the Week & Calendar Calculator](https://calculas.co/date-time/day-of-week-calculator): Find which day of the week any date falls on.
- [Retirement Calculator (Nest Egg & Timeline)](https://calculas.co/date-time/retirement-calculator): Calculate retirement nest egg and safe monthly income.

### Business (5 Calculators)
Tools for profit margins, markups, breakeven analysis, ROAS, and commissions.

- [Profit Margin Calculator](https://calculas.co/business/profit-margin-calculator): Calculate profit margins, markup, and revenue targets.
- [Break-Even Calculator](https://calculas.co/business/break-even-calculator): Calculate units and sales revenue needed to reach profitability.
- [Markup Calculator](https://calculas.co/business/markup-calculator): Calculate retail price, profit, and margin from cost & markup.
- [ROAS Calculator (Return on Ad Spend)](https://calculas.co/business/roas-calculator): Calculate Return on Ad Spend (ROAS) and ad profitability.
- [Sales Commission & Tiered Bonus Calculator](https://calculas.co/business/commission-calculator): Calculate sales commissions, tiered bonus structures, and earnings.

## Features & Technical Verification
- **Precision:** Pure client-side calculations using tested mathematical formulas.
- **Verification:** Unit tested across mathematical edge cases for accuracy.
- **Export Formats:** High-resolution PDF reports, Excel (.xlsx) spreadsheets with formula cells, raw JSON, and URL-encoded scenario links.
- **Tools Specification:** See https://calculas.co/api/openapi.json for programmatic execution endpoints.
- **Comprehensive Index:** See https://calculas.co/llms-full.txt for complete formula definitions and input schemas.