What is a Mood Stability Score?

Mood stability means your emotions stay within a reasonably predictable range from day to day. That doesn’t mean you feel “happy all the time.” It means your week isn’t constantly flipping from amazing to awful to fine to overwhelmed without warning.

The Mood Stability Score (0–100) in this calculator is a simple, practical indicator: higher scores usually show smaller day-to-day swings (and often better consistency in routines like sleep), while lower scores reflect larger swings or rapid up-and-down changes.

• 80–100 (Steady Seas): Your week is emotionally consistent. You still have ups/downs, but they’re manageable.
• 60–79 (Mostly Steady): Normal variability. A couple of “swing days,” but you recover quickly.
• 40–59 (Mixed & Variable): Noticeable swings. Your routines or stressors may be pulling mood around.
• 0–39 (Rollercoaster Week): Large swings or frequent whiplash. It’s worth looking for triggers and adding stabilizers.

• It is not a diagnosis.
• It does not prove “something is wrong.”
• It does not replace professional help if you need it.

How to use this tracker (the “tiny habit” way)

The tracker works best when it’s effortless. The goal is not perfect data; it’s a consistent reflection. Here’s the easiest rhythm:

• Daily: log mood (1–10). Optional: stress + sleep.
• Weekly: check your Stability Score and read the “one lever” suggestion.
• Next week: change just one thing (ex: earlier bedtime or less late caffeine) and see if stability improves.

Small changes become obvious when you track. That’s why “7-day stability” is powerful: it’s long enough to smooth out random bad days, but short enough to feel actionable.

How the Mood Stability Score is calculated

The calculator uses the last 7 days of entries (or fewer if you haven’t logged a full week yet). Each day you log a mood value from 1 to 10. From those values, we compute three main volatility signals:

First we compute your average mood over the window:
Mean mood = (m₁ + m₂ + … + m_n) / n

Variability answers: “How spread out are my moods?”
SD = √( Σ(m_i − mean)² / n )

If your moods are clustered (6, 7, 7, 6, 7), SD is small. If they’re spread out (2, 9, 4, 10), SD is larger.

A week can have the same range but very different “feel.” Example:
Week A: 6, 6, 7, 7, 7, 6, 6 (steady)
Week B: 6, 9, 4, 8, 3, 7, 5 (whiplash)

To capture that, we calculate the average of absolute day-to-day changes:
MAD = average( |m₂−m₁|, |m₃−m₂|, … )

Range = max(m) − min(m)

We start at 100 and subtract penalties for variability:

• Penalty from SD: SD × 12
• Penalty from whiplash: MAD × 8
• Penalty from range: Range × 3

Base score:
Base = 100 − (12×SD) − (8×MAD) − (3×Range)

Habits don’t decide everything, but they matter. We add small bonuses/penalties based on your last 7 days:

• Sleep bonus: if average sleep ≥ 7h, up to +5 (scaled); if ≤ 5h, up to −5.
• Stress penalty: if average stress ≥ 7/10, up to −6; if ≤ 3/10, up to +2.
• Consistency bonus: if you logged ≥ 5 days in the last 7, +5.
• Late caffeine hint: we don’t track timing, but very high caffeine can add up to −2.

Final score is clamped between 0 and 100. The goal isn’t a perfect scientific model — it’s a consistent, understandable number you can improve with small weekly experiments.

Realistic examples (what different weeks look like)

Mood entries: 7, 7, 6, 7, 7, 6, 7
SD is low, day-to-day changes are small, range is only 1. This week usually feels calm and predictable — even if you weren’t “thrilled,” you were steady.

Mood entries: 6, 7, 8, 6, 7, 6, 7
Some movement, one higher day, one lower day — but no major whiplash. Many people land here when life is busy but routines are okay.

Mood entries: 4, 7, 5, 8, 4, 7, 6
The range is 4, and there are several 3-point jumps. This is often what you see with inconsistent sleep, heavy stress, or irregular eating/exercise.

Mood entries: 2, 9, 3, 10, 4, 8, 2
Huge range, high SD, big day-to-day swings. If this happens occasionally, it might just be a chaotic week. If it’s frequent, it’s a strong signal to look for triggers and support.

• Stability is about variance, not “always high mood.”
• Two weeks can have the same average mood but very different stability.
• One change (sleep schedule, less caffeine, more sunlight) can shift stability fast.

What to do if your score is low

A low Mood Stability Score can be frustrating — but it’s also useful. It gives you a clear question: “What would make my next week even 10% steadier?” Here are practical moves that often raise stability quickly:

• Pick a consistent wake-up time (within 30–60 minutes).
• Get light in your eyes early (window or outdoor light).
• Use a wind-down rule: screens off 30 minutes earlier or dim brightness.

• Too much caffeine can amplify anxiety and mood swings for some people.
• Skipping meals can create irritability or crashes (even if you don’t notice it in the moment).
• Overcommitting creates stress “whiplash” — try trimming one obligation.

• 10–20 minutes of movement daily (walk counts).
• A short connection ritual (text a friend, quick call, shared meal).
• One daily reset: journaling, shower, music, breathing, stretching.

Don’t try to fix everything at once. Pick one variable for one week. Track your score. If it improves, keep it. If not, pick the next variable. That’s how a chaotic month turns into a stable baseline.

Frequently Asked Questions

• How many days do I need to log?

  You can calculate a score with as few as 2 days, but it becomes more meaningful with 5–7 days. The tracker uses your last 7 days (rolling window).

• What if I forget a day?

  Totally fine. The tool will use whatever entries exist in the last 7 days. Consistency helps, but perfect tracking is unnecessary.

• Does a high score mean I’m “doing great”?

  It means you’re steady — not necessarily happy. Someone can feel steadily “meh” and still have a high stability score. That’s why we also show your average mood and trend.

• Does a low score mean I have a mental health condition?

  No. Mood swings can happen for many reasons: stress, sleep debt, work deadlines, conflict, illness, travel, and more. If your swings feel intense or unsafe, consider talking with a licensed professional.

• Is my data private?

  Yes. Entries are saved in your browser’s local storage on this device. There’s no account and nothing is uploaded. You can export a CSV or delete the stored entries anytime.

• Can I use this with therapy or journaling?

  Absolutely. Many people use the “notes” field to capture triggers and wins. Your weekly report can help you remember patterns more clearly than memory alone.

• Why does it ask about sleep, stress, caffeine, exercise and connection?

  Those are common “mood levers.” They don’t explain everything, but they often explain enough to make next week easier. The score adds small nudges based on these factors so your report feels actionable.