Exact decimals
Money and calculator maths without floating-point errors.
16 everyday calculators on one fast page — exact to the cent, with no ads and no tracking.
SynthCalc puts 16 everyday calculators on one fast web page: a scientific calculator, units, currency, VAT, tip, loan, savings, BMI and more. Many calculator apps are heavy with ads and trackers, and many round money wrongly because they use floating-point maths, where 0.1 + 0.2 isn't 0.3. SynthCalc does the money and calculator maths with exact decimal arithmetic, so totals, taxes and loan schedules come out to the cent.
It covers what people reach for daily: a scientific calculator with history; a unit converter with 14 quantities, including temperature, decibel power and fuel economy; currency with your own rate and number bases; percentage, discount, VAT, tip splitting and unit price; loans with three repayment methods and a full schedule; savings with compounding, tax and a goal solver; and dates, BMI and body metrics, grade averages, fuel cost and world time.
Every rule is shown where it matters — how loan interest is rounded, how a tip is split so nobody is short, and which formula the BMR uses. SynthCalc is private by design: it makes no network requests, sets no cookies and needs no account. Your inputs and history stay in your browser.
Money and calculator maths without floating-point errors.
Keyboard and keypad, %, mod, powers, trigonometry, logs, factorial and history.
Including temperature, dBm/dBW, fuel economy, torque, and SI vs IEC data units.
Percentage, discount, VAT (round or truncate), tip split and unit price.
Annuity, equal principal and interest-only loans; compounding, tax and a goal solver; full schedule.
Dates, BMI/BMR, grade average, fuel cost and consumption, world time.
Switch language at any time; decimal-comma input works too.
Runs in your browser — nothing to install, no account, no network calls
Your inputs and history are kept in your browser only. Bookmark it or add it to your home screen.
SYNTHETIXMIND builds tools like this, or similar ones, custom-made for our customers: calculators, planners, configurators and quote tools in your brand, on your website, built around your own rules and data.
Ideas, feedback or a custom version for your company? Talk to us.
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