Health & fitness · Medication math
Medication schedule spacing calculator.
Pick every-N-hours or times-a-day, enter your wake and bed times, and get a list of clock times to copy into a phone alarm or a chart.
Not medical advice
This tool only does arithmetic on numbers you type in from your own prescription or package label. It does not recommend any drug, dose or schedule. Follow your prescriber, pharmacist and the label, and ask them before changing how you take any medicine.
Inputs
Dose times
Enter the numbers above.
How the times are spaced
Every N hours is the same gap all day: q6h means every 6 hours, which is 4 doses at 06:00, 12:00, 18:00 and 00:00 if the first is at 06:00. Tick "only while awake" if the label allows skipping the night; the tool then stops at your bedtime. "N times a day" is different: a label for twice or three times a day does not always mean even gaps, so this tool uses a stated assumption. The first dose is at wake time, the last at bedtime, and the rest are spaced evenly between.
Worked example. Three times a day, awake 07:00 to 22:00: that is 15 hours, 2 gaps of 7.5 hours, so doses at 07:00, 14:30 and 22:00. Every 4 hours while awake from 07:00 gives 07:00, 11:00, 15:00 and 19:00 (the next, 23:00, is after bedtime).
Whether a medicine must be taken at fixed gaps, with food or at set times of day is on the label. Follow the label over this spacing, and ask your pharmacist if the schedule is unclear.
Frequently asked questions
What does q6h mean?
q6h is shorthand for every 6 hours, so 4 doses spread across 24 hours, for example 06:00, 12:00, 18:00 and 00:00.
Is three times a day the same as every 8 hours?
Not always. This tool spaces three daily doses evenly across your waking hours, which gives gaps shorter than 8 hours. A label that says every 8 hours means a fixed gap round the clock. Follow the wording on your label.
How are times a day spaced?
The first dose is at your wake time, the last at bedtime, and the others are spaced evenly between. With 07:00 to 22:00 and three doses, that is 07:00, 14:30 and 22:00.
Can I skip the night dose?
Only if your label or prescriber says so. The "only while awake" box shows what the times look like if you do, but it is not advice to skip any dose.
Sources
Checked
Arithmetic only. The waking-hours spacing rule is an assumption stated on the page, not a published standard. Runs entirely in your browser. Nothing you type is sent or stored.
Scope
Some medicines must be taken at fixed gaps or with meals; the label controls. This is a calculation aid, not medical or pharmacy advice, and it does not know your medicine, your health or your prescription. Your label, prescriber and pharmacist decide.