THC Detection Calculator
By Verdant Detox · Updated 2026 · Estimates only — individual results vary
Use this free calculator to estimate how long THC metabolites may remain detectable for a urine, saliva, blood, or hair drug test. Enter your usage pattern, body weight, and metabolism to receive a personalized estimate.
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How Long Does THC Stay in Your System?
When you use cannabis, THC is broken down by your liver into metabolites—primarily THC-COOH. These metabolites can remain detectable after the intoxicating effects have ended.
Detection depends heavily on how often you use cannabis, body composition, metabolism, time since last use, the specimen tested, and the laboratory cutoff.
Detection Windows by Test Type
*Hair tests are commonly discussed as reflecting up to approximately 90 days when a laboratory examines about 1.5 inches of scalp hair. A single exposure may not always be detected.
What Factors Affect How Long THC Is Detectable?
- Frequency and quantity of use—repeated exposure generally produces a longer detection period
- Body composition—THC-related compounds are fat-soluble, so storage and release vary
- Metabolism—individual processing and elimination rates differ
- Hydration and urine concentration—overly diluted urine may be flagged by a laboratory
- Specimen type—urine, saliva, blood, and hair reflect different exposure periods
- Test cutoff—a lower threshold can produce a longer apparent detection window. Learn about the 50 ng/mL threshold.
Supporting Your Body During Abstinence
No method can instantly eliminate THC metabolites. Time and abstinence are the most reliable factors. General wellness measures may support normal body functions while metabolite levels decline naturally.
- Stop cannabis use—continued exposure adds more THC-related metabolites
- Maintain normal hydration—avoid extreme fluid intake that could create a dilute sample
- Eat regular, balanced meals—avoid extreme diets or fasting
- Maintain a consistent routine—sleep and ordinary physical activity support general wellness
- Review the testing policy—specimen type, cutoffs, and confirmation procedures vary
Frequently Asked Questions
A single exposure may remain detectable for several days. Moderate and daily use can produce detection periods measured in weeks, while chronic heavy use may remain detectable longer. Results vary with the laboratory cutoff and individual biology.
Saliva tests generally emphasize more recent exposure than urine tests. The window varies with use frequency, collection quality, the analyte measured, and the program cutoff.
Blood testing generally emphasizes recent exposure. Detection varies with use frequency, the compound measured, and the laboratory method.
Hair testing can assess a longer history of exposure, commonly discussed as up to approximately 90 days when about 1.5 inches of scalp hair is tested.
No. Excessive water intake can produce an overly diluted sample, which may be flagged or require another collection. No fluid routine or supplement can guarantee a negative result.
The calculator provides estimates based on generalized detection windows. It cannot account for every biological or laboratory variable and should be treated as an educational planning tool rather than a prediction or guarantee. For more detail, read the complete THC detection-times guide.
Disclaimer: This calculator provides estimates for informational purposes only and does not constitute medical or legal advice. Individual detection times vary with biology, test sensitivity, and other factors. No tool or product can guarantee passing a drug test. Follow applicable laws and testing policies, and consult a qualified healthcare professional with medical concerns.