1. What is Saltwater Density?

Definition: This calculator computes the density of saltwater in pounds per cubic foot (lb/ft³) based on its specific gravity.

Purpose: It helps marine engineers, oceanographers, and aquatic professionals determine water density for buoyancy calculations, fluid dynamics, and other applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \rho \) — Density of saltwater (lb/ft³)
• \( SG \) — Specific gravity of saltwater (unitless)
• 62.4 — Density of pure water at 60°F (lb/ft³)

Explanation: The specific gravity (relative to pure water) is multiplied by the density of pure water to obtain the saltwater density.

3. Importance of Saltwater Density

Details: Accurate density values are crucial for ship design, buoyancy calculations, ocean current modeling, and underwater construction projects.

4. Using the Calculator

Tips: Enter the specific gravity of saltwater (default 1.025 for typical seawater). The value must be ≥ 1.0.

5. Frequently Asked Questions (FAQ)

Q1: What is specific gravity of saltwater?
A: Specific gravity is the ratio of a substance's density to that of pure water. For seawater, it's typically 1.020-1.030.

Q2: Why 62.4 lb/ft³ for pure water?
A: This is the density of pure water at standard conditions (60°F, 1 atm pressure).

Q3: How does salinity affect density?
A: Higher salinity increases both specific gravity and density. Each 1 ppt (part per thousand) salinity increases SG by ~0.0008.

Q4: What about temperature effects?
A: Warmer water is less dense. This calculator assumes 60°F. For other temperatures, use adjusted specific gravity values.

Q5: Typical density values for seawater?
A: Ocean water averages about 63.96 lb/ft³ (SG=1.025), while brackish water may be 62.4-63.96 lb/ft³.