01 / Tools
How long does weed stay in your system?
Estimate a THC detection window from how often you use, your body weight and the type of test — urine, blood, saliva or hair. Ranges are drawn from published detection-window research. This is a general estimate for education and harm reduction — not a guarantee, and not a way to beat a test.
02 / Calculator
Estimate your detection window
ESTIMATED URINE DETECTION WINDOW
3–7 days
Urine is the most common workplace test and has the longest window, because it detects THC-COOH stored in body fat rather than active THC.
ALL TEST TYPES AT THIS USAGE
- Urine
- 3–7 days
- Blood
- 1–2 days
- Saliva (mouth swab)
- 1–2 days
- Hair follicle
- 7–90 days
This is an estimate, not a guarantee.
Detection windows vary widely with individual metabolism, body fat, hydration, product potency and the specific lab cut-off used. These general ranges are for education and harm reduction only — they are not a way to defeat a test, and not medical or legal advice. If a test matters to you, plan conservatively. 18+.
03 / How it works
What drives the window
The single biggest factor is how often you use. THC breaks down into THC-COOH, which is fat-soluble and accumulates with regular use — so a daily user clears far more slowly than a first-timer. Body weight and body fat, metabolism, hydration and product potency all shift the real number.
Test type matters just as much. Blood and saliva mostly show recent use (a day or few); urine — the common workplace test — has the longest window; hair looks back across ~90 days of growth.
For the full breakdown, read how long dagga stays in your system and CBD and drug tests in South Africa.
04 / Questions
Weed detection FAQ
How long does weed stay in your urine?
For a one-off, roughly 1–3 days; for occasional use about a week; for daily use two to three weeks; and for heavy, chronic use a urine test can stay positive for a month or more. THC-COOH is stored in body fat, which is why urine has the longest window.
Will I fail a drug test if I smoke once a week?
Occasional use (1–2 times a week) is generally detectable in urine for around 3–7 days after the last session, but individual metabolism, body fat and the lab’s cut-off all shift that. Plan conservatively if a test matters.
How long does an edible stay in your system?
Edibles are metabolised through the liver and behave similarly to other THC on a test — detection tracks the same frequency-based urine windows above rather than the format you consumed.
Is this calculator a guarantee?
No. It gives general estimates from published detection-window research for education and harm reduction. It is not a way to defeat a test and not medical or legal advice — real results vary widely between people.