Convert Cubic Metres per Day to MGD (m3/day to MGD)

Formula

MGD = m³/day × 0.0002641720523581

or MGD = m³/day ÷ 3785.411784

Derivation from SI units:

• 1 m³/day = 1/86,400 m³/s; one kilolitre per day (KLD).
• 1 MGD = 10⁶ × 3.785411784 L per day ≈ 0.0438 m³/s.
• 1 m³/day = 0.00001157407407407 m³/s ÷ 0.04381263638889 m³/s per MGD = 0.0002641720523581 MGD

Both units are defined exactly, so the factor is exact. Cubic Metre per Day definition: cubic metre per day; MGD definition: million US gallons per day.

Worked examples

1. A reading of 500 m³/day converts to 0.1320860262 MGD.
   500 m³/day × 0.0002641720524 = 0.1320860262 MGD
2. A value of 10000 m³/day is 2.641720524 MGD.
   10000 m³/day × 0.0002641720524 = 2.641720524 MGD

Where it's used

Cubic Metres per Day are used for STP and ETP capacity (KLD), while million US gallons per day appear in US treatment-plant capacity. Both measure volumetric discharge of rivers, canals and water supply, so the conversion is a fixed factor.

Cubic Metre per Day to other water discharge units

Frequently asked questions

Sources

• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4 (derived units) and Table 8 (non-SI units accepted for use with the SI).
• Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "gallon (U.S.)".

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.