All Online Tools
Browse every free tool on LiteTools: finance calculators, health estimators, image tools, text processors and developer utilities. All run locally in your browser with no signup and no data uploaded.
Every free tool on LiteTools in one place, grouped into five categories: finance, health, image, text and productivity. All calculations run locally in your browser, nothing is uploaded, and no account is required. Each tool page documents the formula, use cases, common questions and known limitations.
Finance & Personal
涉及金额、税负与个人财务决策，建议先读结论再对照自己的合同条款。
- Mortgage CalculatorMonthly payment, total interest and full amortization schedule
- Extra Payment CalculatorSee how much interest you save by paying extra early
- Auto Loan CalculatorMonthly payment with down payment, two amortization styles
- Salary CalculatorConvert gross salary to net pay
- Sales Tax CalculatorAdd or remove sales tax from any amount
- Overtime CalculatorWeekday 1.5x, weekend 2x, holiday 3x pay
- Savings Interest CalculatorSimple and compound interest with year-by-year breakdown
- Compound Interest CalculatorGrowth of principal plus recurring contributions
- ROI CalculatorTotal return, annualized yield and payback period
- BMI CalculatorBody mass index with standard classification
- Body Fat CalculatorUS Navy tape method: body fat %, fat mass and lean mass
- Invoice GeneratorBuild, print or save an invoice as PDF
- Time Zone ConverterConvert times between cities, DST-aware
- BMR CalculatorBasal metabolic rate via Mifflin-St Jeor
- Calorie CalculatorBMR and TDEE for fat loss or muscle gain
- Pace CalculatorPace, finish time and distance with race equivalents
- GPA CalculatorWeighted GPA from course credits and grades
- Debt Payoff CalculatorAvalanche vs snowball payoff strategies
- Retirement Age CalculatorRetirement date under current policy
Everyday Utilities
日常高频使用，计算逻辑简单，结果即时可验证。
- Percentage CalculatorPercent of, what percent, and percent change
- Date CalculatorDays between dates, workdays and countdowns
- Random Number GeneratorDraw picks and samples without duplicates
- Unit ConverterLength, weight, temperature and area in one place
- Age CalculatorExact years, months and days plus zodiac
- Aspect Ratio CalculatorSolve missing dimension or crop ratio
- Word CounterCharacters, words, lines and reading time
- Number Base ConverterConvert between any base from 2 to 36
- JSON Formatter & ValidatorBeautify, minify, sort keys and locate syntax errors by line
- Base64 Encoder / DecoderUTF-8 safe both ways, URL-safe alphabet, file to data URI
- Unix Timestamp ConverterEpoch seconds or milliseconds to local time, UTC and ISO 8601
- Password GeneratorGenerate strong passwords locally
- Discount CalculatorWork out final price after a discount
- Tip CalculatorSplit the bill and calculate tip per person
- Fuel Cost CalculatorTrip fuel cost and cost per kilometer
Related Articles
Tools do the arithmetic; decisions require understanding the underlying logic. These original articles explain the formulas, common misconceptions and the factors that actually matter.
- Extra Mortgage Payments: When It Pays Off
- The Power of Compound Interest, Explained
- BMI Myths: What the Number Does Not Tell You
- Password Strength: What Actually Matters
- Percentage Traps: A 20%% Rise Is Not Undone by a 20%% Fall
- Unix Timestamps: Timezones, Formats and Pitfalls
- Auto Loan Basics Before You Sign
- BMR vs TDEE: Which Number Should You Trust