Updated
50 minutes, rounded up to a 15-minute increment, is 60 minutes. At $120/hr that is $120.00.
The opening bill is 50 minutes worked, a 15-minute increment, and a $120 hourly rate. The minutes round up: ceil(50 / 15) is 4, and 4 × 15 is 60 minutes. The fee is 60 / 60 × $120 = $120.00. You are not billing the raw 50 minutes. The increment you enter is the smallest step the invoice uses, and any partial step rounds up to the next full step.
The second check on this page is 70 minutes at the same 15-minute step and the same $120 rate. ceil(70 / 15) is 5, so the billed minutes are 75. The fee is 75 / 60 × $120 = $150.00. A full hour, 60 minutes, is already on a step, so it stays 60 minutes and $120.00. Fifteen minutes is one step, $30.00. Sixteen minutes is two steps, 30 minutes, $60.00. One minute on a 15-minute increment bills 15 minutes, $30.00.
A 6-minute increment changes the same 50 minutes. ceil(50 / 6) is 9, and 9 × 6 is 54 minutes. At $120/hr that is 54 / 60 × $120 = $108.00. A 1-minute increment bills the 50 minutes as 50 / 60 × $120 = $100.00. The increment box starts at 15 because that is the step in the opening $120.00. Type the step your engagement letter actually names.
This is not a late-fee calculator. It does not add tax. Each minutes box rounds on its own, then the page adds the fees. Entry 2 and entry 3 start at 0, so the opening bill stays the first box: 50 minutes, $120.00. A second entry of 20 minutes at the same 15-minute step and $120/hr bills 30 minutes, $60.00, and the two entries together are $180.00. Set the extra boxes back to 0 to return to the single-entry total.
The day rate guide prices a booked day ($665 at $95 × 7 hours). Per-image price opens at $9.00. Use those when the job is not a minute increment.
Nearby tools: quote a project for a fixed fee from hours and a buffer, coaching package for sessions times hours times rate, sprint price for people times days times hours, and retainer overage for hours past a monthly block. The opening result on this page stays $120.00 for 50, 15, and 120.
Worked example: ceil(50 / 15) × 15 = 60 minutes, and 60 / 60 × $120 = $120.00. 70 minutes on the same increment bills 75 minutes, $150.00.