How to use the Joint Calculator
The calculator estimates how strong your session will probably feel, based on what you're using, how much, how you consume it, and your tolerance. Here's how to use it.
Step by step
- 1
What are you using?
Pick whether you're using flower or concentrate, then choose how you'll consume it — joint, bong, vaporizer or dab. Each method absorbs THC differently, and the calculator takes that into account.
- 2
How much do you intend to consume?
Enter the amount you intend to consume and the THC strength. Not sure about the percentage? Just leave the typical value — it's a good starting point.
- 3
How often do you use cannabis?
Choose how often you use cannabis per week. This sets your tolerance: regular users need more THC to feel the same effect.
- 4
How do you want to feel?
Pick how you want to feel, from Light to Very strong. The calculator then shows the likely intensity, a suggested amount, and whether the estimate matches your target.
What is a THC calculator?
A THC calculator estimates how much THC your body is likely to absorb from a given amount of cannabis, based on potency and consumption method. Unlike a generic cannabis dosage calculator that just adds up the milligrams on the label, the Joint Calculator also factors in how joints, bongs, vaporizers and dabs lose or deliver THC differently — plus your personal tolerance and your own logged sessions.
Understanding the result
The result shows the likely intensity on a scale from Light to Danger zone, the range of possible effects, and a suggested amount for your chosen feeling. You can also peek at the THC maths behind it.
The danger zone
The danger zone isn't something you can aim for — it's a warning. If the estimate reaches it, you're probably using more than you need. Start lower than planned, and wait before having more.
Make it personal
After each session, log how it actually felt. Over time, the calculator learns from your feedback and adjusts future estimates. Sign in to keep your history on all your devices.
Why We Built Joint Calculator
Cannabis dosing should be based on more than guesswork. Joint Calculator is built around published research, consumption data and your own personal statistics to help you better understand how amount, potency, consumption method and tolerance can affect your experience. We take what the research tells us and combine it with what you record from your own sessions, making the estimates more relevant to you over time. Our goal is simple: use actual data to help you have a better experience with cannabis.
Research sources
The absorption ranges used in this calculator are extrapolated from the peer-reviewed research listed below. Individual results still vary.
- Clinical Evaluation of the Cannabis-Using Patient: A Moving Target
- Mechanisms of Action and Pharmacokinetics of Cannabis
- From User Behavior to Laboratory Standards: Cannabis Smoking Machine Protocols from Real-World Puff Topography Data
- Mode matters: exploring how modes of cannabis administration affect THC plasma concentrations and subjective effects
Estimates can vary significantly depending on the person, product, potency, consumption method and setting. Never drive, cycle, operate machinery, or perform tasks that require full attention while impaired. Cannabis laws vary by country and region. Make sure you understand and follow the laws that apply to your country. Joint Calculator provides estimates for informational and educational purposes only. It does not measure your actual THC absorption, predict exactly how you will feel, or provide medical, legal or safety advice.