How Levels Scores and Glucose Metrics Work: A Complete Guide

Levels uses several scores and metrics to help you understand your glucose data. This guide explains how each one is calculated, what the numbers mean, and how they connect to each other.

Baseline glucose: the foundation of your metrics

Your baseline glucose is the starting point Levels uses to measure spikes, calculate scores, and detect periods of stability. Understanding how it works is key to understanding all of your Levels data.

How baseline is calculated

Your baseline is a rolling average of your glucose readings over the previous four hours.
It is personalized to your data and updates continuously as new readings come in.
Levels uses this baseline to detect when your glucose rises significantly above your recent trend.

Why baseline is not a single point on your graph

This is one of the most common sources of confusion. Your baseline is not the lowest visible point on your glucose graph. It is an average computed from the previous four hours of data, which means:

The baseline value may be higher or lower than what you see as the "starting point" of a rise on the graph.
You cannot reverse-engineer a spike value by subtracting the lowest visible point from the peak. The math will not match because the baseline is a rolling average, not a single reading.
For example, if the app shows a +35 spike and your peak was 112 mg/dL, that means your computed baseline at that moment was approximately 77 mg/dL (112 minus 35). Even if the lowest point you see on the graph is 85, the four-hour rolling average was lower.

How Levels defines a glucose spike

A "spike" is a rapid rise in glucose. The term has no clinical definition, but Levels uses a specific formula to label spikes in the app.

The two conditions for a spike

Levels labels a spike when both of the following are true:

Your glucose exceeds 109 mg/dL.
The rise from your baseline to the peak is +30 mg/dL or more.

Both conditions must be met. If your glucose rises 30 points but stays below 109, it is not labeled a spike. If your glucose goes above 109 but the rise from baseline is less than 30, it is also not labeled a spike.

What the +X spike value means

When you see a number like +35 on your glucose graph, that is the difference between your four-hour rolling baseline and the peak of the spike. It is not the difference between the lowest and highest points visible on the graph.

Spike phases

Spiking: Your glucose has exceeded +30 mg/dL above your baseline.
Recovering: Your glucose has crossed back below the spike threshold and stayed there within a one-hour window.
Crashing: Your glucose has dropped 10 points below the pre-spike baseline within 30 minutes of crossing below the spike threshold.

Stability Score (daily score, 60 to 100)

The Stability Score shows how stable your glucose levels were on a given day. It is represented on a scale of 60 to 100, similar to a letter grade.

What range to aim for

Aim for 85 or higher on most days.
Scores above 90 are considered above average.
Think progress over perfection.

What affects your Stability Score

The Stability Score is based on standard deviation, which means it reflects all glucose variability throughout the day, not just labeled spikes. Even smaller fluctuations that do not meet the spike threshold can influence your score.

Your score increases when your glucose remains stable with minimal fluctuation.
Spikes lower your score, but so do frequent smaller rises and dips that add up over the course of the day.
If you regain stability later in the day, your score can recover.
Glucose spikes from exercise do not impact your Stability Score if they are marked as strenuous exercise. Learn more here.

What "Std. Deviation (Variability)" means

Std. Deviation, or Variability, describes how much your glucose fluctuates throughout the day.
Lower variability generally means more stable glucose.
It is calculated by measuring how far your glucose readings vary from your daily average (in mg/dL).

What is an optimal amount of variability

For individuals without obesity or diabetes:

A typical average magnitude of glucose excursions is 26 to 28 mg/dL.
Try not to exceed a 30 mg/dL rise from your pre-meal glucose.
Aim for a post-meal glucose value not exceeding 110 mg/dL.

Glucose Response score (meal score, 0 to 10)

A Glucose Response (previously called zone scores) groups nearby meal logs, activities, and notes so you can understand their combined impact on your glucose. Each Glucose Response gets a score from 0 to 10.

How to interpret your score

10 - Outstanding: Almost no glucose response.
8 - Good: Minimal glucose response.
6 - Moderate: Pay attention. Testing alternate configurations may help.
5 - Poor: High glucose response. Consider eliminating, minimizing, or testing alternate configurations.

How the score is calculated

Levels looks at several factors:

How much your glucose rises: the maximum height of the rise, and the total rise (Area Under the Curve).
How quickly your glucose rises: faster, steeper rises from carb-heavy or processed foods tend to earn lower scores.
Food quality: meals high in protein, fiber, and healthy fats can support better scores. Highly processed foods and those with seed oils can decrease your score. Macros can adjust the score by up to plus or minus 1 point; ingredient quality can reduce it by up to 0.6 points.

Multi-event zones

When you log multiple meals or activities within about two hours of each other, they are grouped into a single Glucose Response and scored together. This is because lifestyle choices interact when they occur close together.

Why the same meal can score differently

Scores are rounded to the nearest whole number, so small algorithm differences can shift the result.
Sleep quality, recent activity, stress, hormones, and time of day all affect your glucose response.

Optimal glucose ranges

For general reference, here are the ranges Levels considers optimal for individuals without diabetes:

Fasting glucose: 80 to 86 mg/dL
Daily range: 70 to 120 mg/dL for approximately 90% of the day
24-hour average: 89 to 104 mg/dL
Aim to rarely go above 140 mg/dL or below 60 mg/dL
Post-meal peak timing: approximately 46 minutes to 1 hour after eating

Tips for improving your scores

Walk after meals. Even a short walk can help blunt a glucose spike.
Try food swaps. Test alternate configurations of the same meal (different macros, different ingredient order).
Change one variable at a time. This makes it easier to identify what helps.
Prioritize sleep. Poor sleep can reduce insulin sensitivity and lead to higher glucose responses.
Manage stress. Elevated stress can raise glucose levels independently of food.
Consider meal timing. Intermittent fasting (12+ hours overnight) can improve glucose stability over time. Talk with your doctor first if you have specific health conditions.

Common questions

Why does the spike number not match my math?

If you subtract the lowest visible point on the graph from the peak, the result will likely differ from the spike value shown in the app. This is because the spike value is calculated from the four-hour rolling baseline average, not from a single visible point on the graph. See the "Baseline glucose" section above for a full explanation.

Why did I not get a Glucose Response?

This usually happens when:

The log is exercise-only or a note without a meal.
The log includes strenuous exercise (the entire Glucose Response is skipped).
There are data gaps from connection issues. See our troubleshooting guide if you notice gaps.

Do exercise spikes affect my Stability Score?

No. Glucose spikes from exercise do not impact your Stability Score if the exercise is marked as strenuous. Learn more here.

What is a good post-meal glucose response?

An optimal response typically returns to your baseline within 90 to 120 minutes. A slower return may reflect reduced insulin sensitivity.

Reminder: Levels is a general health and wellness app. If you have questions or concerns about your metabolic health data, please speak with your doctor.