Theory Exercises

Three-Dimensional (Volume) Unit Conversion

Volume is the amount of three-dimensional space occupied by a substance or object. In daily life we use liters and its prefixes, cl or ml. For bigger quantities and the universal unit system we use cubic meters (m³). Prefixes for liters work in a base 10 system, while cubic meters go from 1000 to 1000.

Recommended symbol for liters

The SI unit liter may be written with either an uppercase L or a lowercase l as the symbol:

  • L (uppercase) → recommended, because it avoids confusion with the digit 1.
  • l (lowercase) → still accepted, but less common in scientific and educational contexts.

The Fundamental Relationship: 1 dm³ = 1 L

The most important relationship in volume conversion is that 1 cubic decimeter (dm³) exactly equals 1 liter (L). This relationship was defined this way to make conversions simpler and more intuitive.

Other equalities:

  • 1 dm³ = 1 L - Exact relationship by definition
  • 1 m³ = 1 000 dm³ = 1 000 L - Large volume conversions
  • 1 L = 1 000 cm³ = 1 000 mL - Small volume conversions
  • 1 cm³ = 1 mL - Medical and laboratory measurements

Liter Notation: Capital L vs. Lowercase l

Recommended notation: Always use the uppercase letter L for liters.

Conversion examples

Desired ConversionEquivalence RelationshipFormula and Calculation
2.5 m³ to dm³1 m³ = 10³ dm³\(2.5 \text{ m}^3 \times \frac{10^3 \text{ dm}^3}{1 \text{ m}^3} = 2.5 \times 10^3 \text{ dm}^3\)
0.8 m³ to L1 m³ = 1 000 L\(0.8 \text{ m}^3 \times \frac{1000 \text{ L}}{1 \text{ m}^3} = 800 \text{ L}\)
150 dm³ to cm³1 dm³ = 10³ cm³\(150 \text{ dm}^3 \times \frac{10^3 \text{ cm}^3}{1 \text{ dm}^3} = 1.5 \times 10^5 \text{ cm}^3\)
3.2 L to mL1 L = 10³ mL\(3.2 \text{ L} \times \frac{10^3 \text{ mL}}{1 \text{ L}} = 3.2 \times 10^3 \text{ mL}\)
0.75 dm³ to mL1 dm³ = 1 L = 1 000 mL\(0.75 \text{ dm}^3 \times \frac{1 \text{ L}}{1 \text{ dm}^3} \times \frac{1000 \text{ mL}}{1 \text{ L}} = 750 \text{ mL}\)
4.6 L to cm³1 L = 1 dm³ = 10³ cm³\(4.6 \text{ L} \times \frac{1 \text{ dm}^3}{1 \text{ L}} \times \frac{10^3 \text{ cm}^3}{1 \text{ dm}^3} = 4.6 \times 10^3 \text{ cm}^3\)
2.8 m³ to mL1 m³ = 10³ dm³, 1 dm³ = 10³ mL\(2.8 \text{ m}^3 \times \frac{10^3 \text{ dm}^3}{1 \text{ m}^3} \times \frac{10^3 \text{ mL}}{1 \text{ dm}^3} = 2.8 \times 10^6 \text{ mL}\)
0.35 hm³ to L1 hm³ = 10⁶ m³, 1 m³ = 10³ L\(0.35 \text{ hm}^3 \times \frac{10^6 \text{ m}^3}{1 \text{ hm}^3} \times \frac{10^3 \text{ L}}{1 \text{ m}^3} = 3.5 \times 10^8 \text{ L}\)
120 dam³ to dm³1 dam³ = 10³ m³, 1 m³ = 10³ dm³\(120 \text{ dam}^3 \times \frac{10^3 \text{ m}^3}{1 \text{ dam}^3} \times \frac{10^3 \text{ dm}^3}{1 \text{ m}^3} = 1.2 \times 10^8 \text{ dm}^3\)

Solved Examples:

Example 1: Convert 0.5 m³ to mL
Method 1: Direct conversion 1 m = 100 cm, so 1 m³ = (100 cm)³ = 1,000,000 cm³ = 1,000,000 mL \(0.5 \text{ m}^3 \times \frac{10^6 \text{ mL}}{1 \text{ m}^3} = 5 \times 10^5 \text{ mL}\) Method 2: Step-by-step using dm³ and L \(0.5 \text{ m}^3 \times \frac{10^3 \text{ dm}^3}{1 \text{ m}^3} \times \frac{1 \text{ L}}{1 \text{ dm}^3} \times \frac{10^3 \text{ mL}}{1 \text{ L}} = 0.5 \times 10^6 \text{ mL} = 5 \times 10^5 \text{ mL}\) Result: 0.5 m³ = 500,000 mL
Example 2: Convert 15 gallons to liters and then to dm³.
Step 1: Convert gallons to liters \(15 \text{ gal} \times \frac{3.785 \text{ L}}{1 \text{ gal}} = 56.775 \text{ L}\) Step 2: Convert liters to dm³ \(56.775 \text{ L} \times \frac{1 \text{ dm}^3}{1 \text{ L}} = 56.775 \text{ dm}^3\) Result: 15 gallons = 56.775 L = 56.775 dm³
Example 3: Convert 2 500 cm³ to all of the following: mL, L, dm³, and m³.
Step 1: Convert cm³ to mL \(2500 \text{ cm}^3 \times \frac{1 \text{ mL}}{1 \text{ cm}^3} = 2500 \text{ mL}\) Step 2: Convert mL to L \(2500 \text{ mL} \times \frac{1 \text{ L}}{1000 \text{ mL}} = 2.5 \text{ L}\) Step 3: Convert L to dm³ \(2.5 \text{ L} \times \frac{1 \text{ dm}^3}{1 \text{ L}} = 2.5 \text{ dm}^3\) Step 4: Convert dm³ to m³ \(2.5 \text{ dm}^3 \times \frac{1 \text{ m}^3}{1000 \text{ dm}^3} = 0.0025 \text{ m}^3\) Result: 2 500 cm³ = 2 500 mL = 2.5 L = 2.5 dm³ = 0.0025 m³
Example 4: Convert 3.5 km³ to different units: m³, L, and mL.
Step 1: Convert km³ to m³ \(3.5 \text{ km}^3 \times \frac{10^9 \text{ m}^3}{1 \text{ km}^3} = 3.5 \times 10^9 \text{ m}^3\) Step 2: Convert m³ to L \(3.5 \times 10^9 \text{ m}^3 \times \frac{10^3 \text{ L}}{1 \text{ m}^3} = 3.5 \times 10^{12} \text{ L}\) Step 3: Convert L to mL \(3.5 \times 10^{12} \text{ L} \times \frac{10^3 \text{ mL}}{1 \text{ L}} = 3.5 \times 10^{15} \text{ mL}\) Result: 3.5 km³ = 3,500,000,000 m³ = 3.5 × 10¹² L = 3.5 × 10¹⁵ mL
Example 5: A storage facility contains 2.5 hm³ of materials. Express this volume in m³, L, and mL.
Step 1: Convert hm³ to m³ \(2.5 \text{ hm}^3 \times \frac{10^6 \text{ m}^3}{1 \text{ hm}^3} = 2.5 \times 10^6 \text{ m}^3\) Step 2: Convert m³ to L \(2.5 \times 10^6 \text{ m}^3 \times \frac{10^3 \text{ L}}{1 \text{ m}^3} = 2.5 \times 10^9 \text{ L}\) Step 3: Convert L to mL \(2.5 \times 10^9 \text{ L} \times \frac{10^3 \text{ mL}}{1 \text{ L}} = 2.5 \times 10^{12} \text{ mL}\) Result: 2.5 hm³ = 2,500,000 m³ = 2,500,000,000 L = 2,500,000,000,000 mL
Example 6: A water tank contains 600 m³ of water. How many 500 mL bottles would it take to contain this amount of water?
Step 1: Convert m³ to mL \(600 \text{ m}^3 \times \frac{10^6 \text{ mL}}{1 \text{ m}^3} = 6 \times 10^8 \text{ mL}\) Step 2: Calculate number of bottles \( \frac{6 \times 10^8 \text{ mL}}{500 \text{ mL/bottle}} = 1.2 \times 10^6 \text{ bottles}\) Result: It would take 1,200,000 bottles of 500 mL each to contain 600 m³ of water