Break the bed into rough rectangles, add up the square footage, then multiply by depth in inches and divide by 324. For curvy borders, length × average width gets you close enough — mulch forgives estimates, and rounding up to the next half yard absorbs the wiggle. Pace it off if you do not have a tape: a normal walking stride is close to 3 feet, which is plenty accurate for mulch.
Example: a curved 30-ft border
| Length × average width | 30 × 5 ft = 150 sq ft |
| × 3-inch depth ÷ 324 | 1.39 yards |
| Rounded up | 1.5 yards |
Or skip the arithmetic — the material calculator does the math for you, section by section, and totals the yards to order.
