THINKVAULT TOOLS · FREE CALCULATORS
Run the numbers before you commit.
Mortgages, deposits, averaging down, currency and bill splits. Pick a tool, enter your numbers and see the breakdown.
- No registration required
- Completely free
- Local calculations
Free practical tools
69 tools
Sort
Finance & Property
10- Compound Interest & FIRE CalculatorCompare compounding, purchasing power, retirement withdrawals and FIRE scenarios.
- Credit Card Payoff CalculatorCompare minimum and fixed payments, payoff time and total interest.
- Buy vs Rent CalculatorCompare buying and renting with optional price growth and holding costs.
- Inflation & Purchasing PowerEstimate future purchasing power, the amount needed to preserve it and cumulative loss.
- Mortgage CalculatorEstimate payments. The model’s fixed 50% DSR is not a local lending approval limit.
- Fixed Deposit CalculatorCompare simple interest, compounding and monthly payouts. Simple interest is the default.
- Personal Loan CalculatorAPR vs flat rate. Early settlement depends on fees and the contract’s rebate rules.
- Savings Insurance IRR CalculatorIRR uses the guaranteed maturity value you enter; the tool does not invent that value.
- Hong Kong AVD Stamp Duty & Upfront Property CostsHong Kong scopeHong Kong residential AVD from 2026-02-26, in HKD; excludes historical instruments, non-residential property and exemptions. Custom mode uses one rate.
- Hong Kong MPF Retirement Savings ProjectionHong Kong scopeHong Kong MPF retirement projection in HKD, with separate capped employer/employee mandatory and voluntary contributions. Withdrawals are initial examples only.
Stocks & Investing
6- Kelly Criterion & Trading ExpectancyEstimate EV and full, half or quarter Kelly sizing from win rate and payoff ratio.
- DCA / Dilution CalculatorEstimate how many shares at the current price would reach your target average.
- Dividend Snowball SimulatorBetaEnter your shares and see when 20-year DRIP compounding covers your principal.
- Risk/Reward & Position SizerBetaSet a loss limit per trade to calculate share count and 1:2/1:3 profit targets.
- Financial Health Traffic LightBetaCheck provider financial indicators. Missing or mismatched statements produce no score.
- Global Market ScheduleBetaCheck reference market schedules and holidays. Unknown dates are not assumed open.
Work & Business
4- Salary & Hourly Rate ConverterConvert annual, monthly, weekly and daily pay to a paid-leave-adjusted hourly rate.
- Leave Pay Estimate — Hong Kong ReferenceHong Kong scopeLeave-pay estimate with Hong Kong reference and 365/260/30-day bases; no automatic statutory adjustments or foreign employment rules.
- Margin, Markup & Break-EvenCompare margin and markup, then calculate break-even sales.
- VAT, GST & Sales Tax CalculatorAdd or extract a custom tax rate. See net, tax and total.
Everyday Life
10- Currency converterEstimate what you receive using reference or manual rates, less fees.
- Discount & unit priceCombine discounts and free-item offers, then compare unit prices.
- Bill splitterEnter payments, service charges and tips to split equally and settle up.
- EV Charging AssistantEstimate charge time, compare session fees and calculate monthly driving costs.
- Electricity Bill, Appliance kWh & EV Charging CalculatorUse your kWh price; no local tariff lookup or guaranteed appliance/EV savings.
- Unit converterConvert length, area, mass, volume and temperature, including square feet and ping.
- What to EatPick one meal from a list of suitable options.
- Recipe Portion ScalerScale ingredients by servings, including fractions.
- Recipe Unit ConverterConvert US and metric units with ingredient density.
- Clothing & Shoe Size ReferenceUse specified Nike adult charts for feet and chest.
Dates & Time
5- Working Days with Hong Kong Public HolidaysHong Kong scopeDeducts Hong Kong public holidays in supported years only. With holidays off, only selected weekends are excluded.
- Date differenceCount days and weeks between dates, with an option to include the start date.
- World time zonesCompare city times, accounting for daylight saving.
- Exact Age & Birthday CalculatorFind your age in years, months and days, plus the next birthday countdown.
- CountdownCount down to a local date and time.
Creative & Digital
21- AdSense Bidirectional Revenue & Traffic CalculatorEstimate ad revenue from traffic or find daily PV for a target income.
- YouTube Ad Revenue & Sponsorship Rate CalculatorEstimate ad earnings from views and RPM. Sponsorship rates are examples.
- Google Flow Slash Prompt & Camera WorkbenchCombine AI video style, camera and character slash prompts to copy.
- Word, CJK Character, Speech Time & AI Token CounterCount CJK characters and words; estimate speech time and AI tokens.
- Local Image Compressor (WebP / PNG / JPEG)Compress WebP, PNG and JPEG images in your browser, then download a ZIP.
- Local Image-to-PDF Builder & Page MergerCombine photos and scanned images into a PDF without uploading them.
- QR Code & WhatsApp Click-to-Chat GeneratorCreate WhatsApp links, website and Wi-Fi QR codes with SVG downloads.
- Morse CodeEncode, decode and play Morse.
- Text TidyTrim, sort or remove repeated lines.
- Letter CaseChange uppercase and lowercase text.
- Special SymbolsPick and copy symbols.
- Vertical TextArrange text in vertical columns.
- URL Encoder / DecoderEncode or decode URI text.
- Base64 TextEncode or decode UTF-8 text.
- JSON FormatterFormat JSON without rounding numbers.
- Color CodesConvert HEX, RGB and HSL colors.
- Chinese Script ConverterConvert simplified and traditional Chinese.
- Typing SpeedPractise typing and compare character rate.
- MetronomePlay a steady beat at a chosen tempo.
- Tone GeneratorPlay a short tone at a chosen frequency.
- Image WorkbenchCrop, resize, convert and sample image colours locally.
Health & Fitness
3
Hobbies & Outdoors
1
Fun & Decisions
9- Coin FlipFlip a coin and view recent results.
- Roll DiceRoll six-sided dice and add the scores.
- Random Number PickerDraw integers from your chosen range.
- Draw LotsPick entries from your own list.
- Random GroupsDivide a list into balanced random groups.
- Decision WheelSet options and percentages, then spin with auto or manual stop.
- Multi-round RaffleDraw winners across several rounds.
- Reaction TimeMeasure a tap after a visual signal.
- Random OrderShuffle a list while keeping every entry.
Understand it. Then try it.
Read the introduction to choose a tool, then follow its guide.