Free business calculators & invoice optimization tools

Calculate tax amount and total payable from any pre-tax amount and tax rate. Great for quickly checking invoice totals.

SEO friendly, free and works directly in your browser.

Estimate interest on overdue invoices or payment plans using a simple interest formula.

Perfect for figuring out fair late-payment or instalment scenarios.

Work out approximate monthly EMIs for loans or big client projects to understand cash flow impact.

Uses the standard EMI formula; no signup or download needed.

Get psychology-backed suggestions for due dates, wording and payment terms to help your invoices get paid faster.

Works perfectly alongside invoices you create with Billable.pro.

Create a simple receipt for payments you’ve collected—fill in the details and copy the ready-made receipt text.

Great for one-off payments, deposits and small client work.

Quickly see discount amount and final price from any original amount and discount percentage.

Useful for limited-time offers and loyal client discounts.

Turn a fixed project budget or monthly target into a realistic hourly rate.

Helps you avoid undercharging for your time.

Set a target yearly income, billable hours and overhead to get a suggested freelance hourly rate.

Designed for independent professionals and agencies.

Enter cost and selling price to see your profit amount and margin percentage.

Great for checking if your quotes are actually profitable.

Estimate a fair late fee based on invoice amount, rate and days overdue.

Helps you keep things fair while protecting your cash flow.

Generate friendly thank you messages to send right after clients pay your invoices.

Strengthen relationships in under 30 seconds.

Answer a few questions and get clear payment terms text you can paste into your invoices.

Set expectations upfront and reduce awkward payment confusion.