Drug Detection Window Calculator (Urine, Saliva, Hair, Blood)
Pick the substance, how often it's used, and the kind of test. You'll get the typical window reported in the research, not a promise. Bodies differ, so treat it as a ballpark, and if it matters, test yourself at home first.
Ad: we may earn a commission if you buy through this link. Information only, not medical or legal advice. Tampering with a drug test can be illegal and usually counts as a refusal. The only sure way to pass is to not use.
How the calculator works
Each answer comes straight from our sourced detection table. We picked the middle of the published ranges and nudged them up for heavier use patterns, because that's what the research consistently shows, especially for THC, which is stored in fat.
Ad: we may earn a commission if you buy through this link. Information only, not medical or legal advice. Tampering with a drug test can be illegal and usually counts as a refusal. The only sure way to pass is to not use.
Why your number may differ
- Cutoff level: a lab using the federal 50 ng/mL THC screening cutoff will flag less than a 20 ng/mL home strip. See cutoff levels.
- Body fat and frequency: THC metabolites build up with regular use.
- Hydration and timing: urine concentration changes through the day.
- Metabolism, age, liver and kidney function.
Embed this calculator
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Questions people ask
Is the calculator accurate for me?
It shows published typical ranges. Nobody can predict an individual result; a home test kit is the only way to check yourself.
Why does hair go back 90 days?
Labs usually cut a 1.5-inch sample from near the scalp. Head hair grows about half an inch a month, so that covers roughly three months.
Ad: we may earn a commission if you buy through this link. Information only, not medical or legal advice. Tampering with a drug test can be illegal and usually counts as a refusal. The only sure way to pass is to not use.
No product can promise you a pass, and the only certain way is to not use. Tampering with a drug test can be illegal and is usually treated as a refusal. We never help anyone beat DOT, federal, safety-sensitive, or court-ordered tests. If substance use is getting on top of you, call the free, confidential SAMHSA National Helpline on 1-800-662-4357 (24/7, English and Spanish), or call or text 988 in a crisis. Source: samhsa.gov.