THC Calculator

Know exactly when you're clear — and get reminders.

Find out how long THC stays in your system, based on your unique profile. Get a personalized clearance estimate for urine, blood, saliva, and hair tests — plus calendar reminders so you never have to guess.

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Do you have a test coming up?

This lets us count down your clearance window and build calendar reminders.

How long does THC stay in your system?

There is no single answer, and that is exactly why a calculator helps. How long THC stays detectable depends on how often you use cannabis, how much you take, your body composition, your metabolism, and the type of drug test you are facing. A first-time user might clear a urine test in a few days. A daily user can stay positive for a month or longer.

THC, the main active compound in cannabis, is fat-soluble. Instead of being flushed out quickly like water-soluble substances, it binds to fat cells and releases back into your bloodstream slowly over days or weeks. This is the core reason clearance times vary so widely from person to person.

THC detection windows by test type

Each drug test measures a different window. Here is what the research generally shows for typical cannabis users.

Test type Typical detection window Best for
Saliva / mouth swab 24 to 72 hours Recent use, roadside checks
Blood 1 to 7 days (up to 25 for heavy users) Recent impairment
Urine 3 days (single use) to 30+ days (daily use) Employment screening
Hair follicle Up to 90 days Long-term use history

What affects how fast you clear THC

Frequency of use

This is the single biggest factor. Occasional users clear THC far faster than daily users, whose fat stores accumulate cannabinoids over time.

Body fat and metabolism

Because THC is stored in fat, people with a higher body-fat percentage tend to retain it longer. A faster metabolism processes and eliminates THC metabolites more quickly.

Consumption method and potency

Concentrates and dabs deliver far more THC per session than a low-strength flower, which extends detection time. Edibles are metabolized differently and can linger as well.

Exercise and hydration

Regular cardio gradually burns the fat cells that store THC. Staying hydrated supports your kidneys. Neither is a magic shortcut, and intense exercise right before a test can briefly raise blood THC levels.

How to use this THC calculator

  • Enter your test date (or skip it for a general estimate).
  • Tell us how often, how much, and how you consume.
  • Add a few details about your body and lifestyle.
  • Choose your test type and get a personalized clearance window.
  • Download calendar reminders to track your countdown.

Looking for lab-tested, compliant products? Explore the Canapuff range.

Disclaimer: This THC calculator provides estimates based on published research and population-level averages. It is not medical advice and cannot guarantee a specific drug test result. Individual clearance varies with genetics, health, and other factors. If a test result carries legal or employment consequences, consult a qualified professional.

Frequently asked questions

How long does THC stay in your system?

THC detection depends on the test type and how often you use cannabis. Urine tests detect THC for roughly 3 days (single use) up to 30 or more days (daily use), blood tests for 1 to 7 days, saliva tests for 24 to 72 hours, and hair tests for up to 90 days.

Why is urine testing so variable?

THC is fat-soluble. It binds to fat cells and releases slowly over time. Heavy users with higher body fat can test positive for 30 to 45 days, while a first-time user may clear in 3 to 4 days.

Does drinking water clear THC faster?

Hydration helps your kidneys flush metabolites and dilutes urine, which can lower test readings. But true clearance requires your body to metabolize THC, and there is no reliable shortcut.

How accurate is this THC calculator?

This tool is based on published pharmacokinetic research and population-level estimates. Individual results vary based on genetics, liver enzyme activity, and body composition. It is not a substitute for professional medical advice or a guaranteed test result.

Does exercise speed up THC clearance?

Regular cardio burns fat cells over time, which gradually releases stored THC. However, intense exercise in the 24 hours before a test can temporarily raise THC levels in your blood, so avoid heavy workouts right before testing.