Compound Interest Calculator
Model compound interest with configurable principal, rate, compounding frequency, and additional contributions. Interactive growth chart with year-by-year breakdown.
Run a Business with The Finance Knife
Money maths — no spreadsheet required
You need to run a business. Founder, freelancer, and creator tools. The Finance Knife delivers 10 purpose-built tools in a single HTML file.
The Finance Knife puts six essential financial calculators and a Scenario Studio into a single HTML file. Model compound interest with Oracle Mode (reverse-engineer your savings goal) and Monte Carlo simulation (see probability-weighted outcomes under volatility). Generate loan amortisation schedules with extra-payment analysis, calculate IRR and NPV, reference 20 currency exchange rates, split VAT inclusively or exclusively, and generate printable invoices — all locally in your browser. Global inflation adjustment lets you see every result in today's dollars. Your financial data never touches a server.
WHAT'S INSIDE
10 tools in a single HTML file
Oracle Mode
Reverse-engineer your financial goals — enter a target amount and get three paths (conservative, balanced, aggressive) showing the monthly contribution needed to reach it.
Monte Carlo Simulation
Run 1,000+ randomised simulations with configurable volatility to see probability-weighted outcome bands. Shows 10th/25th/50th/75th/90th percentiles and goal success probability.
Loan Amortiser
Generate full amortisation schedules for any loan — see principal vs interest breakdown for each payment, total interest paid, payoff date, and savings from extra payments.
HOW IT WORKS
Three steps. No setup.
1
Download the file
Purchase The Finance Knife and download a single HTML file. No installer, no account, no setup.
2
Open in any browser
Double-click to open in Chrome, Firefox, Safari, or Edge. Works on any operating system.
3
Start working
Your data stays in your browser's local storage. Nothing is uploaded. Ever.
COMPLIANCE & GEOGRAPHY
Global
Works in any country. No server dependency, no regional restrictions.
FAQ
Frequently Asked Questions
How does The Finance Knife help me run a business?
The Finance Knife provides 10 interconnected tools for founder, freelancer, and creator tools. Compound interest with Oracle Mode and Monte Carlo simulation, loan amortiser, IRR/NPV calculator, currency table, VAT/tax splitter, invoice generator, and Scenario Studio. Financial tools that never share your numbers.
Do I need an internet connection to run a business with The Finance Knife?
No. The Finance Knife runs entirely in your browser as a single HTML file. All 10 tools work offline.
What is the difference between The Finance Knife and cloud-based alternatives?
Cloud tools store your data on external servers, require subscriptions, and stop working without internet. The Finance Knife is a one-time purchase ($39) that runs locally. Your data never leaves your device.
Can I use The Finance Knife on multiple devices?
Yes. Once purchased, you can use The Finance Knife on any device with a web browser. Copy the HTML file to as many devices as you need.
No cloud One fileOne-time purchase
Get The Finance Knife — $39Sovereignty as a Service