Fill Dirt Calculator

How to Use This Fill Dirt Calculator

This fill dirt calculator estimates the cubic yards, weight in tons, and cost of fill dirt needed to level, grade, or build up an area. Enter the length and width of the fill area and the depth of fill needed. The density field defaults to 95 lbs/ft³ (loose fill dirt) — adjust it for compacted fill or different soil types. Add an optional price per cubic yard or ton to see the material cost.

How to Calculate Fill Dirt

Calculating fill dirt starts with measuring the area and the depth needed to bring it to grade:

Cubic yards = (Length ft × Width ft × Depth ft) ÷ 27

Always add 10–15% to your calculated volume to account for compaction. Fill dirt settles and compacts after placement, so you will need more material than the raw volume calculation shows.

Step-by-Step Example

1. Area to fill: 30 ft long × 20 ft wide
2. Fill depth needed: 4 inches = 0.333 ft
3. Volume: 30 × 20 × 0.333 ÷ 27 = 7.41 cubic yards
4. Add 15% for compaction: 7.41 × 1.15 = 8.52 cubic yards to order
5. Weight: 8.52 × 1.28 = 10.91 tons

Fill Dirt vs. Topsoil — Which Do You Need?

Fill dirt and topsoil are often confused, but they serve completely different purposes. Use this quick guide to choose the right material:

• Fill dirt — Subsoil used for grading and elevation. Low organic matter means it will not decompose or settle much after compaction. Use for: leveling a yard, building up ground before paving, filling a hole or low area, backfilling after excavation.
• Topsoil — The fertile top layer of earth used for planting. Rich in organic matter. Use for: new lawn installation, garden beds, raised planters, over-seeding thin lawns.
• The right order — For a new lawn or garden: fill dirt first to establish grade, then 4–6 inches of topsoil on top for the planting layer.

Fill Dirt Cost Guide

• Clean fill dirt (pickup): $8–$15/yd³
• Clean fill dirt (delivered): $15–$30/yd³
• Free fill: Often available from local excavation contractors — check Craigslist or call local builders. May contain rocks or debris.
• Hauling / spreading labor: $50–$150/hr for equipment; $0.50–$1.50/sq ft for grading services

Tips for Using Fill Dirt

• Compact in lifts — Place fill in 6-inch layers (lifts) and compact each layer with a plate compactor before adding the next. This prevents settling.
• Order extra — Add 10–15% to your calculated volume. Fill dirt compacts significantly after placement.
• Check for debris — Free or cheap fill dirt may contain construction debris. Inspect before accepting delivery.
• Grade away from structures — Slope fill so water drains away from your home's foundation at a minimum 1-inch drop per foot for the first 6 feet.
• Finish with the right surface material — If the filled area will be a driveway, path, or drainage bed, use our gravel calculator to estimate the aggregate layer needed on top.

What Fill Dirt Is — and When to Use It

Fill dirt is subsoil excavated from below the topsoil layer, typically from depths of 2–4 feet or deeper. Because it comes from below the organic-rich top layer of earth, it contains very little organic matter. This is actually what makes it valuable as a structural fill: unlike topsoil, it will not decompose, shrink, or settle significantly after compaction. Fill dirt is stable and predictable.

Use fill dirt for:

• Yard grading and leveling — filling low spots, correcting drainage away from a foundation, or creating a level surface for a patio or outbuilding
• Building pads — raising elevation under a shed, garage, or addition before pouring a concrete slab
• Retaining wall backfill — structural fill behind retaining walls that needs to stay stable under load
• Drainage corrections — building up grade to direct surface water away from structures

Never use fill dirt as the final planting layer. After grading with fill dirt, add 4–6 inches of quality topsoil on top for any lawn or garden area. For topsoil quantities, see the topsoil calculator.

Understanding Compaction: Why You Need More Than You Calculate

Loose fill dirt delivered by a truck is fluffed up by the loading and transport process — it contains air voids between particles. When you place and compact fill dirt in layers, those voids close and the volume shrinks. This phenomenon, called compaction settlement, means you always need to order more fill dirt than the raw volume calculation suggests.

• Sandy fill: compacts approximately 10–15% — add 10–15% to your calculated volume
• Loamy fill: compacts approximately 15–20%
• Clay-heavy fill: compacts approximately 20–30% — the most significant shrinkage

The industry-standard practice is to place fill in 6-inch lifts: spread 6 inches of loose fill, compact it with a plate compactor or vibrating roller, then add the next 6-inch layer. Compacting in lifts ensures uniform density throughout the depth and prevents future settlement. Dumping all fill at once and compacting the top surface leaves loose material deeper in the fill, which will settle over time.