How to use the post-meal glucose timing calculator
Enter the time your meal started and the page returns the one hour and two hour check times on a 24-hour clock. Add a fasting glucose and a post-meal reading and it subtracts one from the other to show the rise in mg/dL. If only one of the two readings is filled in, the page says which one is missing and skips the rise alone.
The reference point is the meal start time you enter. Times are printed with two digits in each field and anything past midnight is labeled as the next day, so a reading such as 24:00 never appears. The rise is a plain subtraction of the two values you entered, with no further adjustment. Current as of October 2026.
This page does not decide whether a reading is high or low. No glycaemic index table is used, and no authoritative figure is given for the effect of eating vegetables before carbohydrates. It handles the check times and the difference between two readings and nothing else, and it is not a medical diagnosis. Interpreting the numbers and adjusting medicines belong with a clinician who sees the full set of results. If you have symptoms of low blood sugar such as shaking, cold sweats or reduced awareness, get medical care without delay.
Frequently asked questions
No. The page goes as far as the check times and the rise as a subtraction. Interpreting the numbers belongs with a clinician who sees your full results and your medicines.
This page counts one and two hours from the meal start time you enter. If you work from a different reference point, enter that time instead.
No authoritative figure for that effect size is given here, and no glycaemic index table is used. The page handles only the check times and the difference between the two readings you enter.