3 min readUpdated for 2026NIST SP 811 Standards

How to Convert Ounces to Grams (oz to g): Precision Step-by-Step

Easily convert ounces to grams for international recipes, postal weighing, parcel shipping, and exact scientific calculations.

⚡Key Takeaways & Quick Summary

  • Formula: Multiply ounces by 28.349523
  • 1 oz = 28.35 g; 4 oz = 113.4 g; 8 oz = 226.8 g
  • Remember: 16 oz equals 453.59 grams (1 lb)

The Multiplier Formula

To convert ounces to grams, multiply the number of ounces by 28.349523125.

Grams (g) = Ounces (oz) × 28.349523

Measurement Standards & Accuracy

Standard Multipliers

Factors based on the 1959 International Yard and Pound Agreement and NIST SP 811.

Sources
  • BIPM International System of Units
  • NIST SP 811 Guide
  • ISO 80000-4
Accuracy & Policy
Standard Exact Multipliers (e.g., 1 lb = 0.45359237 kg)
Reviewed: October 2026 • About our methodology →

Official Government & Scientific Citations

Sources

Verified measurement documentation from NIST, BIPM, and ISO: