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Empirical Formula Calculator

Find the simplest whole-number ratio formula from percent composition or sample masses.

🧱 Empirical Formula Finder

Enter up to 5 elements. Use % composition (must sum to 100%) or actual masses.

⚠ Enter at least 2 elements with values.
Method
% → moles → divide by min → round
Empirical Formula
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🧱 Empirical Formula Steps

  1. Convert percent (or mass) to moles: divide each % by atomic mass
  2. Divide all moles by the smallest number
  3. Round to nearest whole numbers (multiply if needed, e.g. ×2 if you get 1.5)
  4. Write the formula with subscripts

📖 Example

✅ Glucose: 40% C, 6.67% H, 53.3% O

Moles: C=40/12=3.33, H=6.67/1=6.67, O=53.3/16=3.33

Divide by 3.33: C=1, H=2, O=1

Empirical formula: CH₂O

With MW=180: n=180/30=6 → Molecular formula: C₆H₁₂O₆

❓ FAQ

What is an empirical formula?
An empirical formula shows the simplest whole-number ratio of atoms. CH₂O is the empirical formula for glucose (C₆H₁₂O₆). Both have the same 1:2:1 ratio of C:H:O.
How do I get the molecular formula?
Find n = Molar Mass / Empirical Formula Mass, then multiply all subscripts by n. For glucose: n = 180/30 = 6, so molecular formula = (CH₂O)₆ = C₆H₁₂O₆.

🔗 Related

🧱 Molar Mass 🧱 % Composition 🧱 Molecular Formula ⚛️ Stoichiometry
Comprehensive Guide

Understanding Empirical Formula: A Complete Guide

The Empirical Formula Calculator is an essential analytical tool for chemistry students, educators, and laboratory professionals. Accurate Empirical Formula calculations form the backbone of both theoretical studies and physical experiments. Mastering the concepts behind Empirical Formula is crucial for understanding advanced chemical reactions and laboratory procedures.

Why is Empirical Formula Important?

In analytical chemistry, precision is everything. Having a reliable way to compute Empirical Formula saves time, prevents wasted materials, and ensures scientific accuracy.

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Speed
Instant
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Accuracy
100%
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Level
All Levels

Always verify your input units before calculating. Mismatched units (e.g., using mL instead of L) are the most common source of error when determining Empirical Formula!

Common Applications

  • Academic Study: Verifying manual homework calculations.
  • Laboratory Practice: Standardizing lab reagent preparations.
  • Data Validation: Cross-checking experimental data analysis.

Relying solely on the calculator without understanding the underlying formula. Always review the step-by-step breakdown to internalize the mechanics.