Water Truck Calculator

Inputs

Tank Capacity

Common water trucks: 8,000–20,000 L (2,000–5,000 US gal).

Application Rate (L / m²)

Typical dust control: 0.5–2 L/m². Compaction watering varies widely by soil.

Area to Cover (m²)

Spray Efficiency (%)

Allows for wind drift, overspray, and runoff. 80% is a practical field default.

For estimation purposes only. Terms of Use

Result

—

litres of water needed

Tank capacity—

Water needed (US gal)—

Water needed (Imp gal)—

Tank loads required—

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Connected workflow Continue to the earthwork workflow Water requirements carry forward with the project for hauling and production.

Enter the tank capacity, application rate (L/m²), and area to cover.

Water needed = application rate × area ÷ spray efficiency.

Divide by tank capacity and round up for tank loads; convert to US or Imperial gallons if needed.

Formula Used

Water needed = Application rate × Area ÷ Efficiency
Tank loads = Water needed ÷ Tank capacity (rounded up)

Worked Example

A 20,000 m² haul road at 1 L/m² with an 80% spray efficiency and a 12,000 L truck:

Water needed = 1 × 20000 ÷ 0.80 = 25,000 L
Tank loads = 25,000 ÷ 12,000 = 3 loads (rounded up)

When to Use This Calculator

Use this when scheduling water trucks for dust control on haul roads, site prep, or compaction watering — so you know how many loads and how much truck time the job needs.

When Not to Use This Calculator

This is a planning estimate. Actual water demand depends on soil type, weather, temperature, and the number of passes — adjust application rates with field conditions.

Frequently Asked Questions

How much water does dust control really need? ▾

A light application on a haul road is roughly 0.5–1 L/m²; heavier treatments or dry conditions can go higher. Start low and adjust based on what the site needs.

What does spray efficiency mean? ▾

Not all water from the spray bar lands where you want it. Wind, overspray, and runoff typically reduce effectiveness to 70–90%, so we include it in the calculation.