Drywall Mud Calculator
Joint compound in gallons or liters with bucket counts.
What it does
Joint compound covers tape and screws in thin coats, and the buy amount is area times coats divided by maker coverage. This page runs that division and turns gallons into 5 gal buckets, or liters into 20 L buckets in metric.
The default is 500 sq ft with 2 coats at 100 sq ft per gallon. That needs 10 gal, which is two 5 gal buckets. Metric defaults convert the same job to 46.5 m2 and give 37.9 L, or two 20 L buckets.
Coverage is the judgment input. Premix all purpose spreads near the printed rate on flat joints, while topping, hot mud, and textured finishes all lay down differently. Read the pail for your product and lower coverage when much of the work is repair.
Buy a little extra on small jobs. One extra gallon costs less than a second trip, and opened premix keeps when sealed and stored cool.
How to use
- Pick imperial or metric first.
- Enter finished area in the active units.
- Enter coat count.
- Enter maker coverage per gallon.
- Read compound first, then buckets and area.
Formula
- area
- Wall and ceiling area in sq ft or m2.
- coats
- Coat count, often 2 to 3 over tape.
- coverage
- Maker coverage per gallon per coat.
Coverage is sq ft per gallon per coat as printed for the mud type. All purpose, topping, and setting compounds differ, and heavy texture or repair work needs its own margin above the 10% style waste used on shingles.
Worked example
Example: 500 sq ft, 2 coats
500 sq ft (46.5 m2), 2 coats, coverage 100 sq ft per gallon.
- Rate: 500 x 2 / 100 = 10 gal.
- Buckets: 10 / 5 = 2 buckets (5 gal).
- Metric: 46.5 x 2 / 2.4542 = 37.9 L.
- Metric buckets: 37.9 / 20 = 1.9, up to 2 buckets.
- Tool shows 10 gal imperial and 37.9 L metric.
Reference table
| Area | Gallons | 5 gal buckets |
|---|---|---|
| 200 sq ft | 4 gal | 1 |
| 500 sq ft | 10 gal | 2 |
| 1,000 sq ft | 20 gal | 4 |
| 1,500 sq ft | 30 gal | 6 |
| 2,000 sq ft | 40 gal | 8 |
Limits
- Compound only. No tape, bead, or screws.
- One coverage rate per pass. Mixed products need adding.
- Ignores texture and heavy repairs.
- Maker rates vary. Read the pail.
Common mistakes
- Counting one coat where tape needs three passes.
- Using paint coverage for mud.
- Forgetting ceilings and closets in area.
- Rounding buckets down.
- Storing opened premix open so it skins and wastes.
Try it yourself
Quick checks. Answers sit tucked under each question.
200 sq ft, 2 coats?
4 gal (200 x 2 / 100), 1 bucket.
500 sq ft, 3 coats?
15 gal (500 x 3 / 100), 3 buckets.
Questions
How much mud do I need?
Area times coats divided by coverage. Here 500 with 2 coats at 100 is 10 gal.
How many buckets is that?
Two 5 gal buckets for the example. The tool rounds up.
What is that in metric?
37.9 L in two 20 L buckets for 46.5 m2.
Why did I run short?
Taping, corner bead, texture, and repairs all raise use above flat joints.
Does it work in metric?
Yes. Enter meters for liters and 20 L buckets.
Does it include tape?
No. Tape, bead, screws, and sanding waste sit outside compound math.