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Gravel Driveway Calculator · Free calculator

16x20 Gravel Driveway Calculator

Covering 16' × 20' (320 sq ft) with 4" of gravel takes 4.35 cubic yards — about 6.08 tons — with 10% extra. A full 3-layer driveway build for 16x20 is 15.21 tons. Depths, layers, truck loads and fabric are below.

Quick answer

4" gravel
4.35 yd³
Weight @ 4"
6.08 tons
3-layer driveway (10")
15.21 tons
Tandem truck loads (15 t)
2
Geotextile fabric
40 sq yd
Est. gravel cost @ 4"
$248

▍Gravel Calculator

Material
ft
in
ft
in
in
Waste Factor
$
L = 20' 0"W = 16' 0"D = 4"
Cubic Yards
4.35yd³
incl. 10% waste · Bulk delivery: order 4.50 yd³
Cubic Feet
117.33ft³
Area
320.0sq ft
Weight
6.08tons
Weight
12,168lbs
Gravel bags needed
  • 0.5 cu ft bag (~50 lb) (0.5 ft³ yield)235

Gravel for 16x20 by depth

320 sq ft, 10% waste. Crushed stone ≈ 1.4 tons/yd³, ~$55/yd³ delivered.

DepthUseCubic yardsTonsTruck loadsBulk est.
2"Top dressing / refresh2.17 yd³3.041$124
4"Top layer (#57 stone)4.35 yd³6.081$248
6"New pad on firm soil6.52 yd³9.131$371
8"New driveway on soft soil8.69 yd³12.171$481

3-layer gravel driveway build for 16x20

The standard US build for a driveway that won’t rut: big stone base, mid-size stone, fines on top.

LayerDepthCubic yardsTons
#3 stone (1"–2½") base4"4.35 yd³6.08
#57 stone (¾"–1") middle4"4.35 yd³6.08
Crusher run / dense grade top2"2.17 yd³3.04
Total10"10.86 yd³15.21

How the math works

  1. Area: 20 ft × 16 ft = 320 sq ft
  2. Volume @ 4": 320 × (4 ÷ 12) = 106.67 cu ft
  3. Add 10%: 106.67 × 1.10 = 117.33 cu ft
  4. Cubic yards: 117.33 ÷ 27 = 4.35 yd³
  5. Tons: 4.35 × 1.4 = 6.08 tons
  6. Truck loads: 15.21 tons ÷ 15 tons per tandem = 2

Trade pro tips

  • At 4" deep, 16x20 takes 6.08 tons — a single dump truck delivery covers it.
  • Build in layers: 4" of #3 (2"–3") stone, 4" of #57, then 2" of crusher run / dense grade on top.
  • Lay non-woven geotextile over clay soil first — it stops stone from sinking.
  • Crown the driveway ½" per foot so water sheds to the sides.
  • Spread with a box blade and compact each layer before the next.

Frequently asked questions

How many tons of gravel do I need for a 16x20 driveway?

At 4" deep: 6.08 tons. At 6": 9.13 tons. A complete 3-layer driveway (4" #3 + 4" #57 + 2" crusher run) is 15.21 tons. All include 10% extra.

How many cubic yards of gravel for 16x20?

2": 2.17 yd³; 4": 4.35 yd³; 6": 6.52 yd³; 8": 8.69 yd³. 16x20 is 320 sq ft.

How many truck loads of gravel for a 16x20 driveway?

A tandem dump truck carries about 15 tons. 16x20 at 4" (6.08 t) is 1 load; the full 3-layer build (15.21 t) is 2 loads.

How much does a 16x20 gravel driveway cost?

Stone alone at 4" is about $248 (~$55/yd³). A 3-layer build runs roughly $598 in material plus 40 sq yd of fabric; delivery and grading are extra.