Humidity Pack Calculator for Cannabis Jars

How many humidity packs does your weed jar need, and which size? Enter how much flower is in each jar and how many jars you have. You'll get the pack size, the total packs, and the cheapest boxes to buy. The math works for any 2-way humidity pack. The sizes shown are Humidi-Cure® 62%.

Free calculator

Humidity pack calculator for cannabis jars

Sized by flower weight, priced from live store stock.

  • 62% RH 2-way
  • Up to 120 days per pack
Flower in each jar
Jar size 1
Only know the jar size?

Rough estimates for a full jar of cured buds, not pressed down, based on Berlin Packaging's jar sizing guide. Dense buds weigh more, airy buds less. A kitchen scale gives the best answer.

How does the flower feel?

Size chart

Humidity pack size chart

One pack per jar, sized to the flower inside. A bigger pack holds the same 62%. It just has more capacity.

Flower in the jar Pack size Water it can release or absorb Box Stock
Up to 1/8 oz (3.5 g) 1.5g 0.075 g 10 or 20 packs In stock
Up to 1/4 oz (7 g) 3g 0.15 g 10 packs Sold out
Up to 1/2 oz (14 g) 4g 0.2 g 10 or 20 packs In stock
Up to 1 oz (28 g) 8g 0.4 g 10 or 20 packs In stock
Up to 1/2 lb (227 g) 63g 3.15 g 4 packs Sold out

When a size is sold out, the calculator moves up to the next size in stock. Over 1 oz per jar it uses one 8g pack per ounce, which matches the 63g rating for half a pound.

The math

How the calculator works

  1. Flower sets the size, not the jar.The air in a jar holds very little water. What a 2-way pack balances is the moisture moving in and out of the buds, so packs are sized by flower weight.
  2. Up to 1 oz per jar: one pack.You get the smallest in-stock size that covers the flower. Between sizes, it sizes up. There's a 2% allowance, so 28 g and 28.35 g both count as an ounce.
  3. Over 1 oz per jar: one 8g pack per ounce.Rounded up, so you only buy one size. Over 4 oz per jar, it switches to 63g packs whenever they're in stock.
  4. Crispy flower gets one extra pack per jar.Over-dried buds pull more water from the pack while they come back up to 62%.
  5. Damp flower gets no pack yet.A humidity pack isn't a dryer. Finish drying until small stems snap, then jar it.
  6. You pay the lowest price for your packs.It compares every mix of 10 and 20-pack boxes at live prices, including 10% off 2+ boxes. Sometimes two boxes of 10 cost less than one box of 20.

Use this on your site

Writing a curing or storage guide?

You're welcome to link to this calculator or reference the size chart.

Keep reading

Guides for storing cured flower

Humidi-Cure® 62% humidity packs2-way humidity control for jars and bags, sized 1.5g, 4g and 8g.

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