Invoice Calculator: Total, Sales Tax, Discount & Balance Due (Free PDF)

How to calculate an invoice total

Line amounts: multiply each item's quantity (or hours) by its rate.
Subtotal: add up all the line amounts.
Discount: subtract a percentage of the subtotal or a flat amount.
Sales tax: multiply the discounted subtotal by the tax rate, if what you sell is taxable.
Total: discounted subtotal + sales tax + shipping or other charges.
Balance due: total minus any deposit or partial payment already received.

Total = (Subtotal − Discount) × (1 + Tax rate) + Shipping
Balance due = Total − Amount paid

Each line, the discount and the tax are rounded to the cent, the same way invoicing software does it.

Example

A freelance designer bills a website design for $2,400, 8 hours of copywriting at $75 ($600) and 4 stock photos at $15 ($60). The subtotal is $3,060. A 10% discount takes off $306, leaving $2,754. With no sales tax and a $500 deposit already paid, the balance due is $2,254.

If the client pays the full $2,754 by card at 2.9% + 30¢, the fee is $80.17, so the designer receives $2,673.83. Setting aside 25% of that ($668.46) for income tax leaves $2,005.37 to spend.

If the same invoice were taxable at 8%, the sales tax would be $220.32 and the total $2,974.32. Sales tax you collect belongs to your state, so it is not counted in what you keep.

What to put on an invoice

The word "Invoice", a unique invoice number and the invoice date.
Your name or business name and contact details, and the client's name and billing address.
Each product or service with quantity, rate and amount.
Subtotal, any discount, sales tax, shipping, the total and the balance due.
Payment terms and due date (for example Net 30), and how to pay you.

Do freelancers charge sales tax on invoices?

It depends on your state and on what you sell. Most US states don't tax most professional services such as consulting, writing or design, but many tax physical goods and some tax digital products or specific services. Check your state's department of revenue. If nothing you sell is taxable, leave the sales tax rate at 0.

Payment terms and late fees

"Net 30" means the full amount is due 30 days after the invoice date. Shorter terms (due on receipt, Net 7 or Net 15) help your cash flow. If you charge a late fee, say so on the invoice before the work starts, for example 1.5% per month on overdue balances, and check that it's allowed where you and your client are.

Taxes on what you invoice

Nobody withholds tax from a freelance invoice. Moving a fixed share of every payment into a separate account means the money is there when quarterly estimated taxes are due. To find the right percentage for your income, use the 1099 tax calculator. To set your rate in the first place, see the freelance hourly rate calculator.

Frequently asked questions

How do I calculate the total on an invoice?

Multiply quantity by rate for each line and add the lines to get the subtotal. Subtract any discount, add sales tax on the discounted amount, then add shipping or other charges. Subtract deposits already paid to get the balance due.

Is sales tax calculated before or after a discount?

Usually after. Sales tax is normally charged on the price the customer actually pays, so a discount you give on the invoice lowers the taxable amount. This calculator applies tax after the discount.

Can I make a PDF invoice with this calculator?

Yes. Fill in your details and the client's, then press Download PDF / print invoice and choose Save as PDF in the print window. It's free and needs no account.

Is my invoice information stored anywhere?

Only in your own browser on this device, so your details are there next time. Nothing is sent to our servers. Press Start over to clear it.

What does Net 30 mean on an invoice?

The client has 30 days from the invoice date to pay the full amount. The calculator shows the due date for the terms you pick.

How much of each invoice should I save for taxes?

Many freelancers save 25% to 30% of each payment for federal and state income tax and self-employment tax. Your number depends on your income, expenses and state; the 1099 tax calculator works it out.

Last reviewed: 2026-10-13

Invoice Calculator