3×5 shower pan
3×5 ft · 1.5" at drain · ¼"/ft slope · 10% waste · 50 lb bags
- Net volume
- 2.29 cu ft
- With waste
- 2.52 cu ft
- Bags to buy
- 7
A common small shower finish bed. Check your drain instructions for the minimum mud depth before you buy.
How Many Bags of Floor Mud / Deck Mud Do You Need?
Enter the shower or floor size, pick a bed type, and get bags to buy — including slope for center-drain shower pans.
Last updated: July 18, 2026
Quick Presets
Shower = sloped to a drain · Flat = level floor or countertop
Mud depth at the drain — many finish beds start around 1.5"
Floor Mud / Deck Mud Order Summary
9
bags to buy (50 lb)
0.41 cu ft per bag
Order volume3.438 cu ft
Net volume3.125 cu ft
Effective avg. thickness1.88"
Approx. thickness at walls2.13"
Total weight450 lbs
20 sq ft shower · 1.5" at drain · 0.25"/ft slope (center-drain volume) · 10% waste. Bag yields match Quikrete deck mud (50 lb = 0.41 cu ft). Check your drain or liner for the minimum mud depth before you order.
After the bed cures, plan shower tile or grout .
Worked Examples
5×8 flat floor bed
5×8 ft · 1.25" average · 10% waste · 50 lb bags
- Net volume
- 4.17 cu ft
- With waste
- 4.58 cu ft
- Bags to buy
- 12
Level bed under tile — switch to Flat when you are not sloping to a drain.
Deck Mud Coverage Guide
| Thickness | Coverage per 1 cu ft | Notes |
|---|---|---|
| 0.5" | 24.0 sq ft | Thin patches and light leveling |
| 1.0" | 12.0 sq ft | Thinner bonded floor beds |
| 1.25" | 9.6 sq ft | Common floor mud thickness |
| 1.5" | 8.0 sq ft | Many shower finish beds start near this at the drain |
| 2.0" | 6.0 sq ft | Thicker beds or tall walls on large pans |
Quick math: cu ft = sq ft × thickness (in) ÷ 12. One 50 lb bag ≈ 0.41 cu ft; one 75 lb bag ≈ 0.62 cu ft.
Flat Bed vs Shower Pan
| Choice | When to use it |
|---|---|
| Shower pan | Floor slopes to a drain. Enter mud depth at the drain; the calculator adds the usual ¼"/ft slope. |
| Flat mortar bed | Level floors or countertops. Enter the packed thickness you plan to screed. |
Frequently Asked Questions
Figure the mud volume in cubic feet, add a little waste, then divide by what each bag yields. A 50 lb bag is about 0.41 cu ft; a 75 lb bag is about 0.62 cu ft (Quikrete). Enter your shower or floor size above and we round up to whole bags.
It depends on pan size, mud depth at the drain, and slope. A 3×5 shower at about 1.5" at the drain with ¼"/ft slope and 10% waste lands near 7 × 50 lb bags. Use Shower pan mode above for your exact size — do not use a flat average of drain and wall thickness.
About 10 sq ft at 1/2 inch thick (roughly 0.41 cu ft of placed mud). Go thicker and coverage drops — at 1.5 inches, one 50 lb bag covers about 3.3 sq ft before waste.
Once the bed cures, you still need tile, thinset, and grout. Use the Shower Tile or Bathroom Tile calculator for tile counts, then the Grout calculator for the joints.