A stress test that shows its working.
Calmspan exists because most stress quizzes online are invented from scratch. Ours isn't: the score is the Perceived Stress Scale, scored as published, and everything we add on top is labelled as ours.
What this is
Calmspan is a free, browser-based version of the ten-item Perceived Stress Scale (PSS-10) — the instrument researchers reach for when they need a quick, validated measure of how stressful a person finds their life. You answer ten questions about the last month, and you get a 0–40 score, the standard band it falls into, and a breakdown of where the score is coming from.
On top of that we add two things the PSS doesn't provide. The first is a resilience age: a translation of the score into the language people actually think in. The second is an optional HRV overlay for people who own a wearable, which cross-references your resting heart-rate variability against the population curve for your age.
What it isn't
It isn't a diagnosis, a screening tool, or a biological age test. The PSS-10 measures perception — how unpredictable, uncontrollable and overloaded life has felt — and perception is exactly what it says on the label. Two people in identical circumstances can score fifteen points apart, and both scores are valid measurements of two different experiences.
The resilience age is our own construction. It is a readable summary, not a validated biomarker, and we say so on the page rather than burying it in a disclaimer.
How we think about the numbers
Validated where it counts
The 0–40 score and its bands come straight from the published literature. We don't reweight items, drop questions, or invent thresholds that make the result more dramatic.
Separated, not blended
Our additions — the recovery questions and the resilience age — never touch the raw PSS score. They sit alongside it, clearly marked, so you can ignore them if you only want the instrument.
Nothing leaves your browser
Every calculation happens on your device. We don't have a server that sees your answers, no account is required, and sharing a result means sharing a link you generate yourself.
Sources on the page
Every claim that carries weight has a citation next to it, linked to the paper rather than to a summary of a summary of the paper.
Part of a family
Calmspan is the sibling of Helixspan, which estimates projected healthspan — the number of years you are likely to live in good health — from seven modifiable lifestyle factors. Stress is one of those seven. If you want the wider picture rather than the nervous-system-specific one, start there.
Who makes it
Calmspan is written and maintained by a single independent editor with a background in health data and consumer wearables, not a clinician. That matters for how you should read the site: the instrument (the PSS-10) is validated by other people's research, which we cite; the overlay is our construction, which we explain in full on the methodology page. Nothing here is medical advice, and where the literature is thin or contested we say so in the text rather than smoothing it over.
Calmspan is a small independent project, not a clinic and not a device company. It is supported by advertising, which is why you'll see ad slots on the page; nothing about your score changes based on what advertisers want, and we don't sell products off the back of your result.
Corrections are welcome — if you think we've read a paper wrong, tell us.
Changelog
What has changed on the site, newest first. Content is reviewed against the cited literature at least quarterly.
- 5 Oct 2026 — Added four guides: HRV reference ranges by age, measuring HRV without a wearable, PSS-10 population norms, and how each major wearable computes HRV. Published the full methodology page. Added bylines and review dates to every article. Visual refresh.
- 14 Aug 2026 — Resilience-age model v1.1: HRV blend weight lowered from 50% to 45% and the implied-age curve clamped to 18–95 after user reports of implausible outputs at extreme RMSSD values.
- 27 Jul 2026 — Launch. PSS-10 test, optional HRV overlay, six long-form guides, FAQ, privacy policy.