Plan Your Basal Test

Tell us when you want to start and we'll work out the timing for you.

Test Date

Planned Start Time

Test Length

7 hours

(length of time you can fast, skip eating, and avoid exercise)

6 hrs6.577.58 hrs

Display Units

Choose a Test Window

A basal test isolates your background insulin by removing all other variables. Pick the part of the day you want to evaluate.

Test Windows

Midnight — 6:00 AM

🌙 Overnight

Tests how your basal handles the overnight fast and the early morning rise in cortisol (sometimes called the dawn phenomenon).

6:00 AM — Noon

🌅 Morning

Covers the post-dawn window. Useful if your glucose tends to drift in the hours before lunch even without food.

Noon — 6:00 PM

☀️ Afternoon

Tests your midday and early evening basal. Good starting point if your glucose is inconsistent in the afternoon without a clear food cause.

Pre-Test Checklist

All conditions need to be met for a valid basal test. Check each one that applies to you right now.

Last meal was at least 4 hours ago (5 hours for a high-fat meal) i

Food raises glucose directly, independent of your basal rate. If food is still active in your system, any movement in glucose could be from digestion — not from whether your basal is set correctly.

No active bolus insulin on board i

Bolus insulin continues working for 3–5 hours after injection. If it's still active, it will drive glucose down independently of your basal — making it impossible to tell which one is responsible for any change.

Glucose is currently between 80–180 mg/dL i

Starting too low risks a hypoglycemic episode during the test, which would force you to treat and end it. Starting too high means you're already outside the valid range and any correction would invalidate the result.

Glucose trend is stable — no rapid rise or fall in the last 30 minutes i

A glucose that's already moving at the start means something is already affecting it. That movement will be baked into your test data, making it hard to separate from what your basal is actually doing.

No exercise in the last 4+ hours i

Exercise increases insulin sensitivity for hours afterward, which means your basal may appear to be doing more work than it actually does on a non-exercise day. The test would reflect a misleading picture of your typical pattern.

Not sick, not under unusual stress i

Illness and stress both trigger cortisol and other hormones that raise glucose independently of what your basal rate is doing. A test run while sick or stressed will not reflect your normal day-to-day basal needs.

No plans to eat from the test window i

Eating during the test immediately invalidates it. Food introduces a glucose variable that has nothing to do with basal. The test only works if your glucose is moving — or not — purely in response to your background insulin.

No plans to exercise from the test window i

Exercise changes how your body uses glucose and responds to insulin — often dramatically. Any glucose movement during the test would reflect the exercise effect, not your basal rate.

Not sure about one of these? It's better to wait for a cleaner window than to run a test you can't trust.

Test In Progress

Valid

Overnight — Midnight to 6:00 AM

0:00

Elapsed

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Started

0

Readings

Greatest Change from Starting Glucose

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mg/dL up

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mg/dL down

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Countdown to Next Reading

⚠️ Glucose is approaching the boundary. The test may become invalid.

Log a Reading

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mg/dL

Glucose Trace

Reminder: Do not eat, exercise, or correct during the test. If your glucose drops below 70 mg/dL, treat the low and end the test.

Test Invalidated

Something happened during this test window that makes the result unreliable.

Why this matters

The test could not be completed as needed.

Why do tests get invalidated?

A basal test works by isolating your background insulin from everything else. When glucose moves because of food, exercise, a correction, or an illness, there's no way to know whether the change was caused by your basal rate or by the other variable. The result wouldn't reflect your actual basal — it would just be noise.

You can save the partial data for your own reference, or discard it and start fresh when conditions are better.

🟢

Basal Looks Good

Your Glucose Trace — Overnight

Readings logged —

Starting glucose —

Ending glucose —

Net change —

All Readings

This result reflects your glucose data from this test only. It is not medical advice. Always review basal adjustments with your endocrinologist or certified diabetes educator.

Test History

Your past basal tests, most recent first. Tap any entry to see the full detail.