Free Online Calculator Tools
14 toolsOur free online calculator tools cover health, finance, science, and networking. From estimating your blood alcohol content to computing mortgage amortisation schedules, every calculator runs entirely in your browser โ no data is ever sent to a server.
Calculator tools
14Blood Alcohol Concentration Calculator
Free online blood alcohol content (BAC) calculator. Estimate your BAC by weight, gender, drinks, and hours. 100% private, browser-based.
Ovulation Calculator
Free ovulation and fertile window calculator. Enter your last period and cycle length to predict ovulation day, fertile days, and next period.
Mortgage Calculator
Free mortgage repayment calculator. Compute monthly payments, total interest, and full amortization schedule for fixed, adjustable, or interest-only loans.
Water Intake Calculator
Free daily water intake calculator. Find how much water you should drink based on your weight, activity level, and climate instantly.
Lottery Jackpot After-Tax Calculator
Free lottery jackpot after-tax calculator. See your real take-home prize after federal and state taxes for 50+ US and international lotteries.
Microwave Power Conversion Calculator
Free microwave power converter. Recalculate cooking time for different wattage microwaves (600Wโ1200W) instantly in your browser.
Sunscreen SPF Outdoor Time Calculator
Free sunscreen SPF outdoor time calculator. Find how long your sunscreen protects you based on SPF rating, skin type, and sun exposure.
Genetic Traits Probability Calculator
Free genetic traits probability calculator. Predict dominant and recessive trait chances using Mendelian inheritance and Punnett squares.
Sleep Cycle Alarm Calculator
Free sleep cycle alarm calculator. Find the best bedtime or wake-up time based on 90-minute sleep cycles to wake up refreshed.
Subnet Calculator
Free subnet calculator. Get subnet mask, network address, broadcast, IP range, and host count from any CIDR notation instantly.
Math Expression Evaluator
Free JavaScript math expression evaluator. Compute arithmetic, trigonometry, and logarithm expressions safely in the browser.
Natal Chart Generator
Free astrology natal chart generator. Enter your birth date, time, and place to instantly get planet positions, rising sign, midheaven, and houses. 100% private, browser-based.
Caffeine Tracker
Free caffeine intake tracker. Log coffee, energy drinks, tea, and soda to track your daily caffeine against the FDA-recommended 400mg limit. No signup needed.
IQ Test
Free online IQ test with 38 visual reasoning questions. Get an instant estimated IQ range, section breakdown, and no-sign-up browser-based results.
Frequently Asked Questions
Are these calculators free to use?
Yes. Every calculator on this site is completely free and requires no account or sign-up. Just open the page and start calculating.
Do these calculators store my data?
No. All calculations run client-side in your browser. No personal data, health information, or financial figures are transmitted or stored on any server.
How accurate are the results?
Results are based on widely accepted formulas (Widmark for BAC, standard amortisation for mortgages, Marquette for ovulation, for example). They are intended as estimates and not as professional medical or financial advice.