Free · 5 Minutes · No Account
How Old Does Your Body Actually Act?
Free biological age assessment across 8 body systems. The only calculator that layers questionnaire + optional wearable data + optional bloodwork into one multi-facet score. 5 minutes, no account, no email gate.
Based on peer-reviewed frameworks · No account · Practitioner-grade
My Own Test Taught Me Something Weird
In early 2026 I took seven leading biological age tests in a 7-day window on the same blood draw: TruAge by TruDiagnostic (using their SYMPHONY algorithm for organ-system breakdown), GlycanAge, TruMe Labs Age, Viome Full Body, Function Health, and two others. Same blood draw window. Same lifestyle. Same sleep.
They disagreed by 13.1 years.
My chronological age at testing was 30.4. The results ranged from 24.9 (GlycanAge) to 38.0 (TruAge Complete), with InsideTracker InnerAge, Function Health, and Viome Full Body clustered in the middle between 28 and 33. Total cost: $3,143.99.
If you want the receipts, I built a full comparison dashboard showing every result side-by-side with methodology notes and what each test actually measures. I also review the top paid biological age tests and the best epigenetic tests specifically if you want to go deeper on the lab-based side.
That experience shaped how I built this calculator. No single snapshot tells the truth. Trends across systems do.
What Is Biological Age?
Biological age is an estimate of how old your body is actually functioning, compared to how many birthdays you’ve had.
Your chronological age is fixed. It ticks up once a year. Your biological age depends on environment, sleep, nervous system state, nutrition, movement, and stress load. It moves in both directions.
Someone who’s 40 with low systemic stress, clean metabolic function, and strong recovery can test at a biological age of 34. Someone who’s 30 running on cortisol, fragmented sleep, and inflammation can test at 37. The gap between chronological and biological is the signal. It tells you whether your lifestyle is accelerating or decelerating the aging process.
Biological age isn’t a medical diagnosis. It’s a compass.
How Is Biological Age Measured?
All five attempt to quantify the hallmarks of aging (López-Otín framework) and predict healthspan rather than chronological lifespan. Epigenetic clocks like Horvath (2013, Genome Biology), PhenoAge (Levine 2018, Aging), and DunedinPACE (Belsky 2022, eLife) dominate the research literature. DunedinPACE specifically measures pace of aging — how fast you are aging right now — rather than a static age number.
- DNA methylation clocks (Horvath, PhenoAge, DunedinPACE, GrimAge): measure chemical tags on DNA. The most cited approach. Expensive. Can disagree by 10+ years.
- Glycan analysis (GlycanAge): measures inflammatory protein modifications. Faster-responding than methylation.
- RNA and multi-omics (Viome, TruMe): layer microbiome and gene expression data.
- Functional biomarker panels (InsideTracker InnerAge, Function Health): blood-based composites.
- Multi-system questionnaires (this calculator): self-reported inputs across body systems, optionally augmented with wearable and blood data.
| Approach | Example tests | Cost | Time to result | Responds to lifestyle change |
|---|---|---|---|---|
| DNA methylation | TruDiagnostic, GrimAge, Elysium | $250–500 | 4–6 weeks | Slow (6–12 months) |
| Glycan | GlycanAge | $300 | 3–4 weeks | Moderate (3–6 months) |
| RNA / multi-omics | Viome, TruMe | $400–600 | 4 weeks | Moderate |
| Blood biomarker composite | InsideTracker InnerAge, Function Health | $200–500 | 1–2 weeks | Fast (weeks) |
| Multi-facet (this calculator) | Outliyr (questionnaire + wearable + blood) | Free | 5 min | Immediate |
Each approach has tradeoffs. Methylation is precise for a single moment but snapshot-sensitive. Glycan captures inflammation but misses structural aging. Questionnaires catch functional patterns labs miss. The Outliyr calculator is the only tool I know of that layers all three signal families in one assessment: answer the questions, optionally sync your wearable for HRV and sleep data, and optionally attach recent bloodwork for functional-marker refinement.
I go deeper on the paid options in the full biological age test roundup (epigenetic, blood, and microbiome) and in the epigenetic-specific review. This calculator is free and surfaces the lifestyle levers you can actually move.
Why 8 Systems Instead of a Single Number?
A single composite score hides where the problem actually is.
If my composite bio-age is 35, that could mean everything’s running smoothly at 35. Or it could mean my cardiovascular system is 28 and my nervous system is 45, averaged out. One of those needs nothing. The other needs urgent attention.
This assessment scores 8 systems independently:
- Cardiovascular (VO2max proxy, stair-climb, exercise minutes)
- Metabolic (waist-to-height, fasting tolerance, post-meal energy)
- Inflammatory (joint pain, fatigue, allergy burden, recovery speed)
- Immune (infection frequency, recovery time)
- Musculoskeletal (chair stand, push-ups, stair pace)
- Neuro-cognitive (cognition, brain fog, recall)
- Hormonal / Stress (perceived stress, HPA cluster, energy curve)
- Sleep / Circadian (chronotype, sleep quality, consistency)
You get a radar chart across all 8. The lowest scores point to where you’ll get the most leverage from intervention.
Biological Age vs Epigenetic Age vs Phenotypic Age
- Biological age: the umbrella term for how old your body is functionally, vs chronological.
- Epigenetic age: a specific biological age estimate derived from DNA methylation patterns at aging-associated CpG sites (Horvath, GrimAge, DunedinPACE).
- Phenotypic age: a specific biological age estimate derived from blood biomarkers like albumin, creatinine, glucose, CRP, and lymphocyte percentage (Levine PhenoAge, 2018).
- Questionnaire-based biological age (this tool): lifestyle and symptom inputs scored against published aging-biomarker norms.
All four measure aspects of the same underlying phenomenon (accelerated aging), but they respond to lifestyle change at different speeds and capture different signals.
How to Lower Your Biological Age
After working with hundreds of clients and running my own 7-test comparison, the levers that move biological age down, in rough order of leverage:
- Sleep quality and consistency. Fragmented sleep > 3 nights in a row shows up on both HRV and epigenetic markers within 2–4 weeks. Fix sleep before anything else. See my sleep guides.
- Zone-2 cardiovascular work. 150+ minutes per week at conversational-pace effort builds mitochondrial density, improves glucose handling, and moves cardio sub-age faster than any supplement.
- Metabolic flexibility. Walking after meals, eating within a 10–12 hour window, protein at each meal (1g/kg bodyweight minimum). Drops metabolic sub-age within 6–12 weeks.
- Nervous-system downregulation. Daily 10-minute HRV or breathwork practice. The hormonal/stress sub-age often has the biggest gap — because most people under-train the nervous system.
- Resistance training. Twice a week minimum. Musculoskeletal sub-age correlates strongly with all-cause mortality in every longitudinal dataset.
- Evidence-backed supplements: creatine monohydrate (5g/d), omega-3 (EPA + DHA, 2–3g/d), vitamin D (to serum 40–60 ng/mL), magnesium glycinate (300–400mg before bed). See my current supplement stack for the full list.
Retake this assessment every 6–12 weeks. The sub-age drill-down will tell you which of the above deserves your focus this cycle.
Limitations of This Calculator
- Self-report bias. If you misremember your recent exercise volume or underestimate your stress, the score drifts.
- No absolute calibration. Unlike methylation clocks, questionnaire scoring is relative to published norms rather than calibrated against chronological death predictions in longitudinal cohorts.
- Single snapshot. Your HRV this week is not the same as last week. Retaking the assessment every 6–12 weeks converts single points into a trendline.
- Not a diagnostic. A concerning result is a prompt to run labs or see a qualified practitioner, not a medical diagnosis.
The multi-facet version — questionnaire + wearable sync + bloodwork — closes most of these gaps because wearables ground-truth the HRV/sleep inputs and bloodwork catches what you don’t feel.
Who Is This Calculator For?
Anyone who wants a real baseline before spending money on supplements, protocols, or $500 methylation tests.
I built it for biohackers who want to find blind spots, for health-conscious people who want a clear starting point, and for readers who’ve tested their blood and still don’t feel right. The quiz takes about 5 minutes. No account. No email gate on the result.
What Will You Get in Your Results?
- Composite biological age (single number comparing your biological age to chronological)
- 8-axis radar chart showing where each system scores independently
- Shareable result URL (no PII)
- Sub-age drill-down per system with suggested next steps
- Remind-me-in-90-days option so you can track changes over time
Frequently Asked Questions
Is this FDA approved?
No. It’s an educational wellness tool combining peer-reviewed frameworks. Not a medical diagnosis. Always consult a qualified healthcare provider before acting on any result.
Do I need bloodwork?
No. The questionnaire works with no labs or devices. Bloodwork and wearable data (HRV, sleep, activity) are optional layers that refine the score if you have them, but neither is required to get a meaningful result.
How long does it take?
About 5 to 7 minutes for most people. You can skip questions you’re unsure about without penalizing your score.
Is my data private?
Yes. By default, your answers stay in your browser (localStorage) and your result URL is pseudonymous (no personal information embedded). If you choose to attach an email for the 90-day reminder or sync a wearable, that is stored with Outliyr under the terms in the privacy policy: hashed email, wearable tokens kept server-side only, no third-party sale of personal data, and deletion available on request.
How does this compare to DunedinPACE, GrimAge, or InsideTracker InnerAge?
Those are each single-layer lab tests: methylation (DunedinPACE, GrimAge) or blood (InsideTracker InnerAge). The Outliyr calculator is the only biological age assessment that layers three sources of signal in one tool: questionnaire + optional wearable data + optional bloodwork, scored across 8 body systems. The lab tests and this calculator are complementary, not competitors. I use both. See my full 7-test comparison, plus the biological age test roundup and epigenetic test review for the paid options.
How often should I retake it?
Every 6 to 12 weeks is a good rhythm. Changes in sleep, stress, and metabolic markers show up faster than you’d think. The assessment keeps your history so you can compare over time.
What’s the methodology?
Full methodology, formulas, and citations are published openly. Read the methodology page for details on every sub-age and how the composite is weighted.
Created by Nick Urban, CHEK Functional Health Coach L1, HLC2, Integrated Movement Scientist L1, School of Biohacking Certification Instructor, and host of the High Performance Longevity Podcast. Educational wellness tool, not a medical diagnosis. Not FDA-validated. Consult your physician before acting on any result.
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Outliyr Biological Age Calculator
Measure the biological age of 8 body systems in about 5 minutes.
The Outliyr calculator is the only multi-facet biological age assessment that combines a questionnaire with optional wearable sync (Oura, Apple Health, Whoop) and optional bloodwork panel (glucose, HbA1c, hs-CRP, LDL, HDL, triglycerides, ALT, AST). Most online biological age tools score only a single composite. Outliyr returns a composite plus 8 sub-scores so you know which system is aging fastest and which interventions to prioritize.
The 8 body systems scored
Cardiovascular
Heart and circulation: how efficiently your body delivers oxygen during effort and at rest.
Sample question: How winded are you after climbing two flights of stairs — not at all, slightly, very, or cannot finish?
Metabolic
Blood sugar control, insulin sensitivity, and how your body handles carbs and fasting.
Sample question: After a carb-heavy meal, do you crash — never, sometimes, often, or always?
Inflammatory
Chronic low-grade inflammation: joint discomfort, recovery, allergy load, alcohol tolerance.
Sample question: Rate your joint and body pain on a typical day, from 0 (none) to 10 (severe).
Immune
Infection frequency, speed of recovery, and reactivation of dormant viruses like cold sores.
Sample question: How many colds or flu do you catch per year — zero, one-to-two, or three or more?
Musculoskeletal
Functional strength: how easily you stand from a chair, do push-ups, and climb stairs.
Sample question: Standing from a chair without using your hands is: easy, some effort, hard, or you need help.
Neuro-cognitive
Mental sharpness, brain fog frequency, word recall, and bedtime consistency.
Sample question: Rate your mental sharpness today, from 0 (foggy) to 10 (crystal clear).
Hormonal / Stress
HPA-axis tone: perceived stress, afternoon energy dips, and your daily energy curve.
Sample question: How stressed have you felt this month — calm, some stress, high stress, or burned out?
Sleep / Circadian
Sleep quality and chronotype — how restorative your sleep is and when you run best.
Sample question: Rate your overall sleep quality this month, from 0 (terrible) to 10 (great).
What your result looks like
Composite biological age: a single number (for example, 37.4) that represents your overall rate of aging, weighted across all 8 body systems.
Delta vs chronological age: the gap between your biological and calendar age (for example, -4.6 years younger or +3.1 years older). Negative is better.
8-axis radar chart: a visual octagon where each corner is one body system. Corners pulled close to the center = younger; corners pushed out = older. This is the "mini-radar" that makes it obvious at a glance which systems are dragging your overall age up or down.
Strongest system: the body system with the youngest sub-age (for example, "Cardiovascular: 31.2 — 7 years younger than chronological").
Weakest system: the body system with the oldest sub-age and the highest-leverage interventions to reverse it (for example, "Metabolic: 44.8 — focus on zone-2 cardio, time-restricted eating, continuous glucose monitoring").
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