Tools for Finance
90 hand-picked tools for Finance. Free, private, browser-based.
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AI Legal Prompt Library
25 fill-in-the-blank AI prompts for contract drafting, NDA review, legal research, employment law, and IP
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APR to APY Calculator
Convert nominal APR to effective APY (and back) at any compounding frequency — daily, monthly, quarterly, or continuous. Two-way, instant, browser-only.
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Blood Alcohol Content (BAC) Calculator
Widmark-formula BAC estimate from drinks, body weight, sex and time — educational only, never a fit-to-drive verdict — browser-only
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BMI Calculator
Body Mass Index calculator with WHO + Asian classifications — metric and imperial — browser-only
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Bond Price Calculator
Price any fixed-coupon bond from face value, coupon rate, YTM and maturity. Shows premium / discount / par, current yield, and the coupon-vs-face split. 100% in your browser.
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Break-Even Calculator
How many units must you sell to stop losing money? Enter fixed costs, price, and variable cost per unit for break-even units, break-even revenue, and contribution margin — browser-only
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CAGR Calculator
Find the compound annual growth rate between any two values — plus reverse-solve the end value or the years, and see simple vs annualized side by side, browser-only
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Calories Burned Calculator
MET-based calorie burn for 30+ activities — running, cycling, swimming, HIIT, housework — stack and total — browser-only
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Cap Rate Calculator
NOI ÷ property value × 100 = cap rate — solve for rate, value or NOI, with gross rent multiplier — browser-only
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Car Lease Calculator
Cap cost, residual, money factor, term → exact monthly payment with depreciation + finance + tax breakdown — 100% in your browser
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CD Calculator
Certificate of Deposit maturity, interest & effective APY — APY or APR + compounding, early-withdrawal penalty, CD ladder — browser-only
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China Second-Hand House Tax Calculator
China second-hand house transaction tax calculator — contract tax + VAT + personal income tax + agency fee + transfer fee, by city + house tenure + family situation.
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Chinese Numeric Converter
Arabic ⇄ Chinese number — simple (一二三), formal (壹貳參), or amount (金额大写 with 元角分).
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Churn Rate Calculator
Churned ÷ starting customers = churn % — retention, monthly→annual, average lifetime, optional MRR churn — browser-only
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Commission Calculator
Work out sales commission three ways — flat rate, progressive tiers, or reverse-solve the sales you need to hit an income target. Browser-only, shareable.
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Confidence Interval Calculator
Mean and proportion confidence intervals with margin of error, exact z critical values, one-click copy, browser-only
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Correlation Coefficient Calculator
Paste X,Y pairs → Pearson r, r², covariance, regression line and a scatter plot — runs entirely in your browser
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Credit Card Number Deduplicator
Find duplicates and keep one clean copy of credit card numbers from pasted text or uploaded local files.
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Credit Card Number Extractor
Extract, dedupe, and export credit card numbers from pasted text or uploaded local files.
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Credit Card Number List Converter
Convert credit card numbers from pasted text or uploaded local files.
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Credit Card Number List Validator
Validate and explain issues in credit card numbers from pasted text or uploaded local files.
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Credit Card Number Normalizer
Normalize, sort, and prepare credit card numbers from pasted text or uploaded local files.
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Crypto Profit Calculator
Net profit, ROI%, fees, and the break-even sell price for a crypto trade — enter by quantity or by amount invested, both buy and sell fees counted — browser-only
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CSV Column Extractor
Upload or paste CSV, keep only selected columns by name or index, and export a smaller privacy-safe file.
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CSV Data Quality Profiler
Upload CSV or TSV and profile missing values, inferred types, invalid cells, duplicate rows, whitespace issues, top values, and numeric outliers.
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CSV Deduplicator
Remove duplicate CSV rows by full row or selected key columns from uploaded files, locally and safely.
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CSV Filter
Filter uploaded CSV rows by column value using contains, equals, or regex, with local browser processing.
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CSV Header Normalizer
Standardize CSV header rows to snake_case, kebab-case, camelCase, or Title Case before imports and scripts.
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CSV Sorter
Sort uploaded CSV rows by a selected column with numeric-aware ordering and local-only processing.
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CSV Stats Summary
Upload CSV and get a quick Markdown profile of filled, missing, unique, numeric, min, max, and average values.
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CSV ⇄ JSON Converter
Convert CSV to JSON or JSON to CSV — handles quoted commas, newlines in cells, custom delimiter — browser-only
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CSV to Markdown Table
Convert uploaded or pasted CSV into clean Markdown tables with quoted-cell support, locally in the browser.
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CSV to TSV Converter
Convert CSV files to tab-separated values while preserving quoted commas, quotes, and multiline cells locally.
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CSV Transposer
Flip CSV rows and columns from uploaded files or pasted data, with ragged-row handling and local output.
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Customer Lifetime Value Calculator
CLV / LTV for SaaS and e-commerce — simple and SaaS formulas, LTV:CAC health check, one-click copy — runs in your browser
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Date Difference Calculator
Days / weeks / months / years between two dates — plus business-days mode — browser-only
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Debt Payoff Calculator
Snowball vs avalanche — payoff date, total interest, and what an extra payment saves — browser-only
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Debt-to-Income Ratio Calculator
Total monthly debt ÷ gross monthly income, with front-end and back-end DTI, lender bands and one-click copy, all in your browser
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Depreciation Calculator
Straight-line, double declining balance and sum-of-years-digits — full year-by-year depreciation schedule with book value — browser-only
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Dividend Yield Calculator
Share price + annual dividend → yield %, annual/quarterly/monthly income, and yield on cost after years of dividend growth — browser-only
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Duplicate File Finder
Upload a batch and find exact duplicate files by SHA hash locally, with a Markdown cleanup report.
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Electricity Cost Calculator
Power × hours × tariff → kWh and cost per day, month, and year — add multiple appliances, account for standby — browser-only.
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Expected Value Calculator
E[X] = Σ x·p — enter outcomes and probabilities, get expected value, variance and standard deviation, all in your browser
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Expense Tracker
Expense tracker — log spend, categorize, see monthly totals, all in your browser.
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File Checksum Compare
Paste an expected checksum, upload a file, and verify SHA digest matches locally before installing or sharing.
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File Hash Calculator
Compute SHA-1, SHA-256, SHA-384, or SHA-512 hashes for uploaded files entirely in the browser.
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File MIME Type Inspector
Upload files and inspect filename, size, browser MIME type, extension, and magic-byte signature locally.
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Fiscal Year Calculator
Pick a date and a fiscal-year start month — get the FY label, quarter, day count and exact start/end dates, browser-only
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Freelance Hourly Rate Calculator
Back into the hourly rate you must charge from your target salary, business expenses, billable hours, profit margin, and taxes — browser-only
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Future Value Calculator
Project the future value of a lump sum plus regular contributions — full time-value-of-money math, year-by-year, browser-only
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Home Affordability Calculator
Income + debt + down payment + rate → the max home price a lender's 28/36 rule will actually approve — browser-only
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IBAN Validator
Check any IBAN with the ISO 7064 mod-97 checksum and a 60-country length table, formatted output, one-click copy, browser-only
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Ideal Weight Calculator
Devine + Robinson + Miller + Hamwi formulas, side by side, plus the healthy BMI weight band — metric and imperial — browser-only
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China Income Tax Calculator
China personal income tax calculator — monthly, annual, with 5 insurance + 1 fund deductions.
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Inventory Turnover Calculator
COGS ÷ average inventory = turnover ratio, plus days sales of inventory (DSI) — type the average directly or let beginning + ending fill it in — browser-only
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Invoice Generator
Free invoice generator — clean PDF in your browser, no signup, no watermark.
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LLM Pricing Calculator
Estimate daily and monthly LLM spend from tokens, request volume, and editable model prices.
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Local File Workbench
Triage a mixed batch locally for file type mismatches, duplicate candidates, metadata privacy, archive risks, and next-step tools.
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Luhn Validator
Check any number against the Luhn (mod 10) algorithm, see the doubling math step by step, or compute the missing check digit, all in your browser
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Mortgage Calculator
Mortgage calculator — monthly payment, total interest, amortization schedule, early payoff scenarios.
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MPG Calculator
Distance + fuel → MPG (US/UK), L/100km, km/L, all at once + cost per mile/km — browser-only
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Net Worth Calculator
Add up assets, subtract debts, see your real net worth — with a debt-to-asset ratio and composition bars, all computed in your browser
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NPV Calculator
Discount every cash flow back to today — net present value, IRR, payback period, per-period present value — browser-only
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Number to Words
Spell any number in English — cheque amounts, ordinals, British vs American "and" — 100% browser-only
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Odds Converter
Decimal, fractional and American odds with implied probability, all four update live as you type
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Office Document Inspector
Inspect DOCX, XLSX, and PPTX package structure for macros, media, embedded objects, custom XML, and size hotspots.
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Password Generator
Generate strong, cryptographically random passwords and passphrases — entirely in your browser.
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Payment Processing Fee Calculator
Stripe, PayPal, Square fees — see what lands in your account, and gross-up to net any target — 100% in your browser
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Percentage Calculator
5 common percentage calculations — "x% of y", "x is what% of y", percentage change, increase/decrease — instant, browser-only
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Percentile Calculator
Any percentile P plus Q1 Q2 Q3, IQR, five-number summary, box plot and 1.5×IQR outliers, browser-only
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Barbell Plate Calculator
Target weight → exactly which plates to slide on each end — kg & lb, with a live barbell diagram — browser-only
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Pregnancy Weight Gain Calculator
Pre-pregnancy BMI + week → IOM recommended total gain, the by-week target, and an on-track check — singleton & twins — browser-only
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Present Value Calculator
Discount a future sum or a level annuity back to today — PV = FV / (1 + r)^n, single sum or annuity, browser-only
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Rent Affordability Calculator
How much rent can you actually afford? 30% rule, landlord 3× gate, and a debt-aware 50/30/20 number — all client-side
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Rent vs Buy Calculator
See whether buying beats renting and investing the difference — net cost, terminal equity, and the break-even year, all in your browser
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Retirement Savings Calculator
Project your retirement pot from age, savings, monthly contributions, return and inflation — with a 4% safe-withdrawal income, growth curve, and goal-gap check. Browser-only.
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Routing Number Validator
Check a 9-digit ABA routing number with the public 3-7-1 checksum, read its Federal Reserve routing symbol, one-click copy, browser-only
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Rule of 72 Calculator
Estimate doubling time from a rate (72 ÷ r), or the rate from a target time — side by side with the exact ln(2)/ln(1+r) figure — browser-only
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Salary Raise Calculator
Turn a raise into real numbers — new salary by year/month/hour, dollar increase, and the inflation-adjusted raise that tells you if you actually came out ahead
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Sales Tax Calculator
Add or remove US sales tax — split state + local rates, real 2024 state base rates on tap, browser-only
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Simple Interest Calculator
I = P × r × t — solve for interest, principal, rate, or time, plus total and a simple-vs-compound gap — browser-only
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Startup Runway Calculator
Cash in bank ÷ burn rate = months left. Enter balance, monthly spend, and revenue (with optional growth) for runway, cash-out date, and the date you must start fundraising — browser-only
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Take-Home Pay Calculator
Gross → net pay, any country — your own tax rate, pre-tax & post-tax deductions, reverse-solve — browser-only
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Unix Timestamp Converter
Unix timestamp ⇄ human date — seconds / milliseconds / ISO 8601 — UTC and local — browser-only
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TSV to CSV Converter
Turn tab-separated files into standards-friendly CSV with proper quoting, download, and local processing.
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Unit Converter
Convert between length, weight, temperature, area, volume, speed, time — instant, browser-only
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Waist-to-Hip Ratio Calculator
WHR = waist ÷ hip, scored against the WHO health-risk bands by sex, with an optional waist-to-height check — runs entirely in your browser
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Weekly Report Generator
Weekly report generator — fill blanks, get clean markdown, no AI hallucination.
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Weighted Average Calculator
Any value × weight pairs, weighted mean = Σ(value×weight)/Σweight, plus plain average and per-row contribution, browser-only
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ZIP Manifest Inspector
Read a ZIP central directory locally and flag traversal paths, encryption, duplicate names, and risky ratios.