How to calculate cubic feet for washer & dryer
Washer and dryer drums are cylinders. To calculate cubic feet from interior dimensions, use the cylinder formula:
V = π × radius² × depth, with all measurements converted to feet (divide inches by 12).
The calculator above accepts inch input directly and converts internally for you.
Worked examples
Example 1: A 22 × 14 inch top-load washer drum
π × (11)² × 14 ÷ 1,728 ≈ 3.07 ft³.
Example 2: A 27 × 16 inch front-load washer drum
π × (13.5)² × 16 ÷ 1,728 ≈ 5.30 ft³.
Example 3: A 27 × 30 inch dryer drum
π × (13.5)² × 30 ÷ 1,728 ≈ 9.94 ft³.
Washer & dryer size guide
| Capacity | Conversion factor | Worked example |
|---|---|---|
| < 2.5 ft³ washer | Compact | Apartment, 1–2 person |
| 3.0–4.0 ft³ washer | Top-load standard | Couples, small families |
| 4.0–5.0 ft³ washer | Front-load standard | Families of 3–5 |
| 5.0–6.5 ft³ washer | Mega-capacity | Large families, comforters |
| < 4.0 ft³ dryer | Compact | Apartment |
| 6.0–7.5 ft³ dryer | Standard | Pairs with 3.5–4.5 ft³ washer |
| 7.5–9.0 ft³ dryer | Large | Pairs with 4.5–5.5 ft³ washer |
Tips and considerations
Don't over-pack
A washer rated at 4.5 ft³ doesn\'t mean filling 4.5 ft³ of clothes. Loads should fill roughly 75% of drum volume — overpacking reduces cleaning effectiveness.
Match dryer to wet weight
Wet clothes weigh 2–3x dry weight and need volume to tumble. A dryer drum 1.5–2x the washer volume avoids long drying times and wrinkles.
Common mistakes to avoid
- Using outside dimensions. A “5.0 ft³” washer rating is the drum capacity. Outside cabinet dimensions are larger and not directly comparable.
- Comparing washer and dryer ft³ as the same metric. Dryer capacity is usually about 2× the washer's — wet clothes expand as they tumble dry.
- Forgetting that “king sheets” needs at least 4.5 ft³.Marketing language for “extra capacity” varies — actual cubic feet ratings are what matters.
- Treating top-load and front-load capacity as identical.Front-loaders pack more efficiently — a 4.5 ft³ front-load typically washes more than a 4.5 ft³ top-load.
Related concepts and calculators
Laundry-appliance capacity ties into a few related calculators:
- Refrigerator and freezer — same internal-volume logic in different cabinets.
- Cubic feet to liters — washing machine tubs are sometimes specced in liters in metric markets.