How to test your basal rate

Step 1. Eat an early dinner (e.g. 6pm). Avoid alcohol and high fat foods.

Step 2. Chill. Avoid food, insulin, stress, and exercise after dinner. If you have a low or a high you will need to treat it but otherwise try to remove those extra variables.

Step 3. Test at bedtime (e.g. 10pm) and make a note of the reading.

Step 4. Test overnight. If you don’t have a CGM, set alarms throughout the night (it’s a headache but it will be worth it!). Your goal is to identify whether your sugars are slowing creeping up or down overnight or spiking/dropping at a certain point.

Step 5. Test when you wake up. Make a note of the reading.

Step 6. Repeat several times. You're looking for a trend.

Step 7. Analyze and adjust. See if there is a pattern and consider adjusting your basal dose accordingly. These are rough recommendations and may not be right for everyone. Talk to your diabetes team before making adjustments if you're unsure.

⬆ If blood sugar rises overnight → Increase basal insulin by ~10% 

⬇ If blood sugar drops overnight → Decrease basal insulin by ~10% 

✅ If stable (within ~1.6 mmol/L or ~30 mg/dL) → Your basal is correct!

If you’re a pump user, adjust basal 1-2 hours before the spike or drop.

Step 8. Observe for a few days. Keep an eye on your bedtime and morning glucose to see if the adjustment is successful.

Step 9. Run a daytime basal test? You may also want to run this test at a different time of day to work out if your insulin requirements are, say, higher in the afternoon. All you need to do is pick a fasting window when there is no bolus operating. 

🥐 Breakfast test: Eat a late dinner, skip breakfast, observe from 8 AM–12 PM.

🥪 Lunch test: Eat before 8am, skip lunch, observe from 12 PM–4 PM.

🍜 Dinner test: Eat before midday, then observe from 4 PM–8 PM.