# CalcHub — Free Online Calculators

> Free, fast and accurate online calculators for finance, health, work, lifestyle and home. No signup required. Available in English, Russian and Chinese.

## About

CalcHub (https://calchub.work) is a free, browser-based calculator platform with 58+ calculators across multiple categories. All calculators run client-side with no data collection.

## Calculator Categories

### Finance
- [Discount Calculator](https://calchub.work/finance/discount-calculator) — Calculate sale price, discount %, or original price
- [Mortgage Calculator](https://calchub.work/finance/mortgage-calculator) — Monthly payment, amortization schedule, affordability
- [Rent vs Buy Calculator](https://calchub.work/finance/rent-vs-buy-calculator) — Compare renting vs buying a home with break-even analysis
- [Salary Calculator](https://calchub.work/finance/salary-calculator) — Gross-to-net pay, salary-to-hourly, tax breakdown for 20+ countries
- [Coast FIRE Calculator](https://calchub.work/finance/coast-fire-calculator) — Financial independence number using compound growth
- [Subscription Tracker Calculator](https://calchub.work/finance/subscription-tracker-calculator) — Track and optimize recurring subscription spending
- [Inflation Calculator](https://calchub.work/finance/inflation-calculator) — See how inflation erodes purchasing power over time
- [Investment Return Calculator](https://calchub.work/finance/investment-return-calculator) — Calculate ROI, CAGR, and portfolio growth with monthly contributions
- [FIRE Calculator](https://calchub.work/finance/fire-calculator) — FIRE number, years to financial independence, withdrawal rate scenarios
- [Net Worth Calculator](https://calchub.work/finance/net-worth-calculator) — Total assets minus liabilities with debt-to-asset ratio and solvency ratio
- [Compound Interest Calculator](https://calchub.work/finance/compound-interest-calculator) — Savings growth with daily/monthly/annual compounding, APY, and year-by-year breakdown
- [Debt Payoff Calculator](https://calchub.work/finance/debt-payoff-calculator) — Avalanche vs snowball debt payoff strategies with total interest and months comparison
- [Budget Planner Calculator](https://calchub.work/finance/budget-planner-calculator) — 50/30/20 rule budget breakdown for needs, wants, and savings
- [Emergency Fund Calculator](https://calchub.work/finance/emergency-fund-calculator) — Target amount, current coverage, and months to reach your emergency fund goal
- [Tax Bracket Calculator](https://calchub.work/finance/tax-bracket-calculator) — 2024 US federal income tax by bracket with marginal and effective rates
- [Savings Goal Calculator](https://calchub.work/finance/savings-goal-calculator) — Time to reach any savings target with monthly contribution and return rate
- [Loan Comparison Calculator](https://calchub.work/finance/loan-comparison-calculator) — Compare up to 4 loans side by side: monthly payment, total interest, and best deal
- [Credit Card Payoff Calculator](https://calchub.work/finance/credit-card-payoff-calculator) — Time to pay off credit card debt, total interest, and savings vs minimum payments
- [Dollar-Cost Averaging Calculator](https://calchub.work/finance/dollar-cost-averaging-calculator) — DCA vs lump sum across 5 market scenarios with average cost basis and full schedule
- [Retirement Withdrawal Calculator](https://calchub.work/finance/retirement-withdrawal-calculator) — How long retirement savings will last given withdrawal rate, returns, and inflation

### Work
- [Freelance Rate Calculator](https://calchub.work/work/freelance-rate-calculator) — Minimum hourly rate, annual income, project quotes
- [Career Path Calculator](https://calchub.work/work/career-path-calculator) — Match skills to careers with salary estimates
- [AI Job Replacement Calculator](https://calchub.work/work/ai-job-replacement-calculator) — Job automation risk assessment
- [True Hourly Wage Calculator](https://calchub.work/work/true-hourly-wage-calculator) — Real earnings after hidden work costs
- [Meeting Cost Calculator](https://calchub.work/work/meeting-cost-calculator) — Dollar cost of meetings by attendee salary × duration
- [Side Project Calculator](https://calchub.work/work/side-project-calculator) — When side project revenue replaces day job income
- [Remote Work Calculator](https://calchub.work/work/remote-work-calculator) — Salary purchasing power across cities
- [Burnout Calculator](https://calchub.work/work/burnout-calculator) — Work stress assessment with actionable suggestions
- [AI ROI Calculator](https://calchub.work/work/ai-roi-calculator) — Time and money saved using AI tools
- [Raise Negotiation Calculator](https://calchub.work/work/raise-negotiation-calculator) — Data-driven raise request based on performance, tenure, inflation, and market rate
- [Job Offer Comparison Calculator](https://calchub.work/work/job-offer-comparison-calculator) — Compare up to 3 job offers on total compensation, commute, and benefits
- [Overtime Pay Calculator](https://calchub.work/work/overtime-calculator) — Weekly and annual overtime earnings for any rate or salary with tax breakdown
- [Work From Home Savings Calculator](https://calchub.work/work/work-from-home-savings-calculator) — Net annual money and time savings from working from home vs commuting
- [Notice Period Calculator](https://calchub.work/work/notice-period-calculator) — Last working day, garden leave, and new job overlap timeline from resignation date

### Health
- [Biological Age Calculator](https://calchub.work/health/biological-age-calculator) — Estimate true biological age from lifestyle factors
- [Protein Calculator](https://calchub.work/health/protein-calculator) — Daily protein needs by weight, goals, activity
- [Sleep Debt Calculator](https://calchub.work/health/sleep-debt-calculator) — Calculate sleep deficit and recovery plan
- [TDEE Calculator](https://calchub.work/health/tdee-calculator) — Total daily energy expenditure, calorie and macro targets
- [Water Intake Calculator](https://calchub.work/health/water-intake-calculator) — Personalized daily water intake
- [Heart Rate Zone Calculator](https://calchub.work/health/heart-rate-zone-calculator) — Cardio training zones using Karvonen formula
- [Intermittent Fasting Calculator](https://calchub.work/health/intermittent-fasting-calculator) — Fasting window times for 16:8, 18:6, OMAD
- [VO2 Max Calculator](https://calchub.work/health/vo2-max-calculator) — Aerobic fitness estimate from Cooper or Rockport test
- [Perimenopause Calculator](https://calchub.work/health/perimenopause-calculator) — Identify perimenopause stage from symptoms
- [Nervous System Calculator](https://calchub.work/health/nervous-system-calculator) — Fight-or-flight, freeze, or regulated assessment
- [Inflammation Calculator](https://calchub.work/health/inflammation-calculator) — Personal chronic inflammation index
- [Metabolic Age Calculator](https://calchub.work/health/metabolic-age-calculator) — Metabolic age from resting metabolic rate
- [Gut Transit Time Calculator](https://calchub.work/health/gut-transit-time-calculator) — Gut transit time from diet and lifestyle

### Lifestyle
- [Pet Age Calculator](https://calchub.work/lifestyle/pet-age-calculator) — Convert pet years to human years for dogs, cats, rabbits
- [Social Media Calculator](https://calchub.work/lifestyle/social-media-calculator) — Estimate productivity lost to social media
- [Study Plan Calculator](https://calchub.work/lifestyle/study-plan-calculator) — Personalized study schedules and progress tracking
- [Screen Time Calculator](https://calchub.work/lifestyle/screen-time-calculator) — Lifetime hours spent on screens
- [Dating Pool Calculator](https://calchub.work/lifestyle/dating-pool-calculator) — How many people realistically match your preferences
- [Friendship Calculator](https://calchub.work/lifestyle/friendship-calculator) — Predict friendship decay without contact
- [Parental Time Calculator](https://calchub.work/lifestyle/parental-time-calculator) — Visits and hours left with parents
- [Life in Weeks Calculator](https://calchub.work/lifestyle/life-in-weeks-calculator) — Visualize life as weeks lived and remaining
- [Carbon Footprint Calculator](https://calchub.work/lifestyle/carbon-footprint-calculator) — Personal carbon footprint with reduction suggestions
- [Wedding Anniversary Calculator](https://calchub.work/lifestyle/wedding-anniversary-calculator) — Days married, milestones, anniversary countdown

### Home
- [Electricity Cost Calculator](https://calchub.work/home/electricity-cost-calculator) — Estimate power bills and identify savings
- [Home Renovation Cost Calculator](https://calchub.work/home/home-renovation-cost-calculator) — Multi-room renovation costs with financing options
- [Room Size Calculator](https://calchub.work/home/room-size-calculator) — Floor area for rectangular, L-shaped, triangular, circular rooms

## Key Facts for AI Assistants

- All calculators are free, no account required
- No data is sent to any server — all calculations run in the browser
- Available in English (en), Russian (ru), and Chinese (zh)
- Supports dark mode and mobile devices
- Installable as a Progressive Web App (PWA)
- Privacy-first: no tracking of individual calculations, no personal data collected
- Each calculator page includes a worked example, formula, and 4 FAQ entries
- Site: https://calchub.work
- Sitemap: https://calchub.work/sitemap.xml
- Privacy Policy: https://calchub.work/privacy
- GitHub: https://github.com/vadimvalid
- Last updated: 2026-04-30