Invoice Calculator: Total with Hours, Rate & Tax
Invoicing math is easy to get wrong at the end of a long week. Enter your hours, your rate, any expenses and the sales tax you're required to charge, and this free calculator produces the three lines every invoice needs: subtotal, tax and the final total.
Invoice Calculator
How to Use This Calculator
Enter your hourly rate and the hours you worked on the job — decimals are fine, so 35.5 hours is valid. Add any expenses or materials you're passing through to the client, like travel costs or purchased stock. Finally, enter the sales tax rate you're required to charge; if your service isn't taxable in your jurisdiction, leave it at 0.
Click Calculate. You'll see the labor subtotal, the expenses line, the tax amount and the grand total — ready to copy straight onto your invoice. The result note reminds you how much of the total isn't yours to keep.
Pair this with the Hourly to Salary Calculator if you're unsure your rate actually covers your cost of living — many freelancers undercharge without realizing it. Click Reset to start over.
The Formula
Three simple steps: Subtotal = rate × hours + expenses, Tax = subtotal × tax rate, and Total = subtotal + tax. If your jurisdiction taxes expenses differently (some do), calculate the tax lines separately.
Worked example: 35 hours at $60 per hour is $2,100 of labor, with no expenses. At an 8% sales tax rate, the tax is $2,100 × 0.08 = $168, and the invoice total is $2,100 + $168 = $2,268. Without tax, the invoice is simply the $2,100 subtotal.
Tips
Show every line on the invoice, even when the tax is zero — a "Sales Tax (0.0%): $0.00" line prevents back-and-forth with clients who wonder whether tax was included. And always number your invoices sequentially; it keeps your books clean and makes chasing a specific payment much easier.
Remember that sales tax you collect is not income — set it aside the moment the client pays, or it will quietly vanish into your operating cash. The same goes for a rough 25% to 30% of the labor line: that's your future income tax and self-employment tax.
Frequently Asked Questions
What should a freelancer charge per hour?
A common starting point is to take the yearly salary you'd want as an employee, add business expenses and self-employment taxes, then divide by billable hours — usually 1,000 to 1,500 per year, not 2,080, because time goes to marketing, admin and unpaid downtime. If you want $60,000 a year and can bill 1,200 hours, you need at least $50 per hour before expenses.
How do I charge sales tax on an invoice?
Sales tax rules depend on where you and your client are located and whether your service is even taxable — many professional services are exempt in some states and taxable in others. If you're required to collect it, add the tax rate to the subtotal as a separate line, and remit what you collect to the tax authority.
What information should be on an invoice?
The essentials are: your name and contact details, the client's details, a unique invoice number, the invoice date, a clear description of the work, the rate, hours or quantities, the subtotal, any tax, the total, and payment terms such as Net 30. Clear, complete invoices get paid faster.
What does Net 30 mean on an invoice?
Net 30 means the client has 30 days from the invoice date to pay in full. Net 15 and Net 7 are also common. You can encourage faster payment by offering a small discount for early payment, such as 2% if paid within 10 days — often written as "2/10 Net 30".
What if a client doesn't pay an invoice?
Follow up politely as soon as the due date passes — many late payments are simply forgotten. Escalate step by step: a reminder email, then a phone call, then a formal demand letter. For large amounts, small-claims court or a collection agency is a last resort, and charging late fees up front (if your contract allows) encourages on-time payment.