Running your own business means doing your own maths. Day rates, tax estimates, late payment interest, cash flow gaps — it's relentless.
I built these tools because I got tired of searching for them. They're all free, work in your browser, and don't require an account.
The Toolkit
1. Day Rate Calculator
Work out what you should charge per day based on your target annual income, working days, tax, and profit margin.
2. Self-Employed Tax Calculator 2025/26
Full breakdown of Income Tax, Class 2 and 4 NI, student loan, and take-home pay.
3. Late Payment Interest Calculator
Calculate statutory interest and compensation under the Late Payment of Commercial Debts Act 1998. Most freelancers don't know they can charge this.
4. Cash Flow Forecast
Plan income vs expenses month by month. Spot cash gaps before they happen. Export to CSV.
5. Business Expense Tracker
Track expenses by HMRC category. Spending breakdown, running totals, CSV export. Uses localStorage.
6. Mileage Allowance Calculator
HMRC-approved rates for cars, vans, motorcycles, bicycles. See your actual tax saving.
7. Invoice Generator
Create a professional invoice, preview it, download as PDF. VAT toggle, multiple line items.
8. Payment Reminder Generator
Generate chase emails at three levels: friendly, firm, final notice. Copy-paste ready.
9. Client & Project Tracker
Track clients, projects, invoices. Dashboard with revenue stats. CSV export.
10. MTD Readiness Checker
Find out if Making Tax Digital affects you. Personalised action plan. MTD deadline: 6 April 2026 — 22 days away.
Why free?
Because freelancers already pay for enough software. These tools cover the basics that shouldn't require a monthly subscription.
All built with vanilla HTML/JS. No frameworks, no backend, no tracking. Your data stays in your browser.
What tools do you wish existed for freelancers? I'm always looking for the next one to build.
Top comments (0)