Here’s How Long Weed and Edibles Stay in Your System (Calculator)

This guide details how long cannabis and cannabis edibles stay in blood, urine, saliva, hair and sweat. As a bonus, we’ve included an online THC detox calculator which will tell you exactly in how many days you’ll be THC-free.

Most of the tests in use today detect THC in levels above 50 ng/dL, so until you get below that level you will keep testing positive.

Body fat percentage plays a huge role in how quickly you are able to flush THC out—the more body fat you have, the longer the THC will stay in your system as that’s where it’s stored.

Only THC is detectable in tests while other cannabinoids (such as CBD) are not detectable in all common tests.

Here’s how long weed stays in your system (Chart)

This chart provides an estimate of how many days it will take to flush THC out of your system.

How long does weed stay in your system (Chart)

Precise THC detox calculator

While the chart does provide a decent basic overview, it’s not exactly precise. This is the most accurate THC detox calculator online (based on ProfOfPot‘s formula) as it takes into account two things that influence the metabolism of THC the most: Body fat percentage and urine THC metabolite levels.

Body fat (%):

Urine metabolite level (ng/mL):

Time to clear THC (days):

As you can see, to use this calculator you’ll need to know your urine metabolite levels. Metabolite levels of frequent users hover at around 200-250 ng/mL, measured one day after using cannabis.

The only way to get exact numbers is by using a home kit THC test—don’t go for the most basic one as you’ll need a “multi-level” test that shows THC levels in ng/mL. Here is a cheap multi-level test I found on Amazon.

If you don’t know what your body fat percentage is, take a look at this visual comparison for a rough estimate.

Chart to assess body fat levels visually

How long is cannabis detectable in the system?

This depends on the testing method and the frequency of use. Here’s a quick overview.

Urine testing

THC can be detected in urine from 7-70 days.

Urine testing does not look for THC, but a nonpsychoactive metabolic intermediate—THC-COOH.

After using cannabis, our liver metabolizes THC into THC-COOH which is then stored in urine.

Again, how long THC stays in urine depends on the frequency of use.

If you’ve used marijuana just once, THC will stay in your urine for about 7 days.

If you ‘ve smoked 2 to 4 times recently but didn’t use it afterward, THC will be detectable in your urine for 10 to 18 days.

If you regularly smoke 5 or 6 times a week you can expect the metabolite to remain in your urine from 30 to 48 days.

Medical marijuana users and daily recreational users need a bit more time to completely detox—about 50 to even 70 days.

Blood testing

THC is detectable in blood from 1 to 7 days.

THC is only detectable in blood for a short amount of time, and so this method of testing is not that popular anymore.

After smoking, THC runs through the blood and into the fat cells, where it stays for longer periods of time.

In general, if you’re not a regular smoker and you only took a few puffs, THC will be detectable in your blood for about one to two days.

If you used cannabis a few times in the past week, THC will be detectable in your blood for about 3 days afterward.

Yet, if you are a regular, everyday user you’ll need around 7 days to flush THC out completely.

Hair testing

THC is detectable in hair for up to 90 days.

In fact, THC is detectable from just a single hair sample taken 1.5 inches from the scalp, which makes the hair test really scary and accurate—it can detect even picograms of THC.

Note: If your first hair sample tests positive for weed, they might ask you to provide a second sample.

Saliva testing

THC can be detected in saliva for 1-7 days

Saliva marijuana tests are usually used by the police, through devices like the Dräger 3000.

THC and its metabolites can be detected in saliva just an hour after consuming cannabis.

If you only used marijuana once, it can be detected in your saliva for the next 24 hours.

If you are an occasional user THC can be detected in your saliva for up to 72 hours.

If you are a regular heavy consumer (or a daily medical user), saliva THC test will turn positive for up to a week.

Roadside saliva tests have been very controversial recently. The problem is that you can test positive to THC without even being high, so it’s still very difficult to determine if the driver is actually impaired or not.

Sweat testing

THC is detectable in sweat for 7-28 days.

Sweat tests are not that common and they are usually used for monitoring patients during drug rehab treatments and employment programs.

THC metabolites can be detected in sweat for about one to four weeks.

This depends on two factors: How much sweat one produces and how much they smoke.

Also take into account environmental factors, such as temperature and air humidity.

Here’s how this test works:

THC sweat patches are applied to the skin and are usually worn from 7 to 14 days. After that period, patches are taken off for testing.

The amount of produced sweat is subjective, and so the accuracy of this testing method is somewhat limited. And it’s hard to control if someone wore the patch all the time, of course.

How long do edibles stay in your system?

Consumption method is very important when it comes to cannabis testing.

For example, when you eat a cannabis brownie, it takes much longer to get “high” when compared to smoking.

When you take an edible, cannabis has to go through the entire digestion process. Afterward, cannabinoids get processed by the liver and that’s when they enter the blood.

That’s why edibles stay in the system for 7 to 30 days.

Just 5 days after taking an edible, 80 to 90% of THC is flushed out but the remaining 10% can stay there for up to 4 weeks.

How to flush THC out quickly and detox from cannabis?

The best way to flush THC out of your system and pass the test is pretty simple—total abstinence for a set period of time.

If you know you’re going to be tested for THC, I suggest you reverse engineer the chart above and stay cannabis-free for that time period.

If it’s already too late and you don’t have the time, there are a few things you can do to speed up the detox process.

These tips could help, but there are no guarantees they will work.

Take note that research showed that people with a fast metabolism, lower body fat percentage and lower BMI can flush THC out faster than people with standard BMI.

But, here is what you can do.

1) Drink plenty of water

Staying hydrated is essential for your health in general. So if you want to flush marijuana out your system, start drinking a lot of water a few days before the test.

Keep in mind that drinking a lot of water can make your urine clear, so this could look suspicious as well.

2) Eat the right foods

As THC is stored in fat, you’ll need to avoid fatty and greasy foods as well as things rich in sugar and sodium. That means no junk food and red meat.

You’ll need a lot of food rich in fiber and antioxidants so stick to fruits, vegetables and whole grains to detox faster.

Also, vitamin C should be your new best friend. Lemonades and citrus juices are full of electrolytes which are great detoxing agents. Tea will also help you flush THC out, so drink a few cups of green, black or white tea a couple of days before your test.

Vitamin B3 is great when you’re looking to cleanse your system from just about anything. Avocados and potatoes are one of the biggest natural sources of vitamin B3 (also known as niacin).

3) Exercise and sweat

Cardio is the best way to burn fat, which is also where THC metabolites live. By exercising, we sweat more, excrete fluids and we eventually speed up the THC detox.

A workout that mixes cardio and strength would be the best to flush marijuana out, starting a few weeks prior to testing.

But, there is one tricky thing when it comes to exercising. Don’t do it on the day of testing. In fact, try to avoid all exercise a couple of days before the big day.

Even though exercise burns fat, that process also releases more THC metabolites into your blood, which could be a bad choice for the testing day.

If you’re really worried about the test, a sauna can also do wonders.

4) Get a lot of sleep

It’s now common knowledge that cannabis relieves stress and induces sleep. However, if you have to take a drug test you’ll have to get some rest without weed.

When we sleep, our whole body recovers for the following day. It’s our own, natural detox mechanism.

So, a few days (or weeks) before taking the test, try to get as much sleep as possible. Give yourself a few nights off and try to go to bed earlier than usual.

Categories Basics

Journalist with a decade-long experience of using cannabis for stress relief. Her spare time is mostly divided between dancing, traveling and reading.

38 thoughts on “Here’s How Long Weed and Edibles Stay in Your System (Calculator)”

  1. I am 56 yrs. old. I thank the younger generation for keeping Cannabis alive. My passion is deep and my story is long about cannabis use. Thank God for this wonderful herb.

    • Hi Adrianna,

      Thank you for your lovely comment. Hope you found this article useful. We would like to hear more about your long experience with cannabis.



  2. Ciao helena,se possibile volevo sapere che tipo di analisI a cosa servono e se possibile che ésca fuori qualche traccia di sostanza stupefacente.GRAZIE
    Prelievo ematico per: EMOCROMO,GOT,GPT,YGT,SIDEREMIA,CTD

  3. Hi good story glad I found it. One slight correction on the length of time THC Cannabis can remain in the system specific to saliva tests. Here in Australia and many other countries they use a Drager Saliva testing machine and it has a 99% accuracy. However there is a challenge between detection and impairment. BMI is a standard element of the Drager as you mention thanks folks miss that, and thus detection time can be WEEKS not 7 days per Drager. We have had many court cases on it here also. Here in Australia the law is not based on impairment only “the presence of an illicit substance” in this case THC. Just part of the mess that is Cannabis law reform herre in Australia.

  4. I’m with Loren above.
    Re the roadside testing; I believe you can refuse it, it’s not like a breath alcohol test which is mandatory, and enforcable.
    Some would say our whole system of justice and law is illegitimate, seeing as how they are now profit driven corporations that must trick you into contracting with them…
    Can’t say I’ve ever tried it, I try and keep beneath the radar.
    A good many years ago in a country far far away I was involved with a friendly fraternity of motorcycle enthusiasts.
    Their mantra was ‘do not talk to police, do not incriminate yourself’…
    But what I’m doing, I’m going to see my friendly doctor, and inform Her I have ‘discovered’ medical marijuana, hence why it’s been so long I haven’t come back for opioid pain killers. I’m not waiting for the govt’s permission for them to grow, manage and denature a vegetable. Thank you I am quite capable and self sufficient, if the need arises.
    So, unlike their denatured product branded, licensed ‘safe’ product, my source is as God gave.
    So, if ever I do get entrapped in a roadside test, I can refer to my doctor, that I do indeed have a condition where I am self medicating with MM, albiet black market.
    Which will make it a lot easier than getting a note from my doc after the imaginary event.
    I’m 56 and I’m not really on the cops radar, but best to pre-empt the situation.
    I have genuine medical needs which have been diagnosed, but I rejected all their treatment plans in favour of old reliable, my first love, we’ve been together now 35 years!

  5. I weigh 115 have a high matabolism, and very skinny with barley any fat. If I smoked weed once and have a drug test in 9 days will I pass? Please need a answer soon I’m nervous

  6. I am 6’3” and 270 lbs, i smoked extracts 97% THC and smoked marijuanna everyday for 3 months. I have been clean for 60 days, bit i am still teating dirty, will i be clean by 70 days or will my usage push me to a longer rimeline to be clean of THC?

    • Andy, there’s no telling exactly especially because you’ve been smoking concentrates and since we don’t have a baseline. Most tests test positive on anything above 50 ng/dL, so until you get below that level you will keep testing positive. Body fat percentage plays an important role in how quickly you clear THC. To calculate exactly how long it’ll take you to flush THC out, I would skip over to the bottom of this post and follow the 3 step tutorial:

  7. I have a question that I haven’t seen answered in the hundreds of forums I’ve been perusing so far:

    I started smoking about 5 years ago (daily smoking for the past 4). I stopped shaving my legs 7 or 8 years ago. Since my leg hair was at maximum length, would it still test positive for THC?

    From what I understand THC is deposited through the root into *growing* hair. So I’m wondering if I have max length body hair from before I started smoking would it test clean?

    (If you have an account on another MJ forum site, please ask for me lol, thanks!)

  8. High! I haven’t shaved my legs in years. The last time was probably 3 years before I started smoking cannabis daily. I tried it once about 3 or 4 months after I shaved for the last time, and then didn’t smoke again for years. Since my leg hair was at maximum length before I started smoking would it still be possible for the hair to have THC(COOH)? Any info is useful, and if you have an account on any other MJ forums can you please ask there too? haha Thanks!

  9. Hi I smoked weed for about 5 months and I weigh 130 and have a terribly high metabolism for a 19 year old guy can someone tell me when it will be out of my system

    • Yes, depending on your metabolism and how often you use edibles (or smoke weed in general), it can show up on a saliva testa up to a week after consumption.

  10. Hi, i have been a frequent user, for a year or so. I lost my drivers licence for it. I ussually smoked about 3 g, a week. I stopped about 10 ago completly. I was wondering how long should i wait to get tested, to pass the urine test? I am pretty thin about 65 kg at 180cm.

  11. Hi, I occasionally used THC e-cigarette(almost never) and tried 2 hits last night and felt nothing. But I had a bite of MJ chocolate around half month ago and I am going to have a test after a week. Can I pass that test? I am 182cm and 80kg, 23 years old.

  12. Hi I had one 10 mg cookie and kinda puked after I got high. Have test in a week. What should I do. Little body fat,work out 6 times a week.age 24

  13. My last edible was a gummy 46 days ago. I haven’t smoked or consumed any weed since then.I have a pre employment urine drug test in 3 days.. before I stopped I would eat 5mg gummies once every other night to help me sleep. I passed 2 different brands of drug test. My only concern is that the home test test at 50ml.. Do u think I’m good even if they test for lower amounts

  14. I have been clean sense dec 8th it’s now feb 4th and last night I had half of a gummy edible it’s way under 20mg let’s say 10 mg and I took a home test today and I failed how long will test dirty for I’m 5’2 125lb female

  15. I have a question, the last time I had one puff of weed in early december and haven’t had any more, would any of it still be in my system?

  16. I had 1 chocolate candy filled with carmel edible of christmas day. I have a urine test on valentines day. Im female…5’8 190lbs…will i test dirty. That was my only time eating 1.

  17. I take a couple puffs of my vape nightly for the last few months. Compared to smoking joints, how long should I expect that to be out of my system? Please and thanks?

  18. Hi, I haven’t smoked in 5 years. I took 4-5 puffs on 01/27. Will it still be in my system? Planning on taking at home test today. I am 30, weigh 173, 5’6’m and BMI is around 30%. Thanks.

  19. hi i took five hits off a blunt on feb 23 this yr. im only about 125 and it was my first time how long would it take to leave my system?

  20. Hey guys,

    I’ve been smoking everyday, multiple times a day for about two years now. I had my last puff at the end of January and have been clean since. I’ve also been on the keto diet and working out. Lost around 20lbs at this point. I have a drug test within the next week or so. What are the odds I pass? Any information would be greatly appreciated!

  21. Don’t smoke at all went on vacation and had 1 edible of 5 mg. Haven’t had anything since! How long would it take for me to pass a hair follicle test?

  22. HI!

    So I have a cartridge that was rated at 96% THC which I stopped smoking about 8 days ago. I’m 6′ 5″ and weigh 193 pounds. This coming week I have a couple interviews both of which will drug test me if I take the position. Do you think I will pass? To know how much I smoked, I would maybe hit it once or twice a week if that. Each hit would only be for 3 seconds max as well. I’m guessing that once I take my first drug test I will be about 12-16 days clean. Also I only drink water, tea, and homemade lime juice. I also started to run last week, and am currently on a diet of not having any junk food at all.


  23. I’ve been smoking everyday for years till the past 2 weeks which has been just here and there. I have a job interview within the next week and they do a mouth swab. Do you think I’m safe?? Please help

Leave a Comment