高速＆高精度な化学ツール
Molar Mass & Mole Converter
化学式を入力するだけで、分子量、モル質量、元素質量パーセント、原子数を小数第4位まで瞬時に計算します。
118
118元素
Nₐ
4桁精度
100%
100% ブラウザ処理
分子量
全118元素対応 · IUPAC 2021標準原子量
クイック例:
上に化学式を入力して分子量を計算します
Step-by-Step Guide
How to Calculate Molecular Weight
Calculate chemical formula mass in three simple steps.
Input a Chemical Formula
Type any chemical formula — H₂O, C₆H₁₂O₆, NaOH, or even complex structures with parentheses and brackets. The molar mass calculator identifies each element, resolves nested groups, and counts every atom. All 118 elements from the periodic table are supported.
NaOH
↓
Na × 1O × 1H × 1
FAQ
Frequently Asked Questions
Find answers to common questions about molecular weight calculations and chemistry formulas.
Molar mass is the mass of one mole of a substance, expressed in grams per mole (g/mol).
To calculate molar mass: (1) identify each element in the formula, (2) look up each element's standard atomic weight from the IUPAC periodic table, (3) multiply each atomic weight by its atom count, and (4) sum all products.
The Avogadro constant (Nₐ) is exactly 6.02214076 × 10²³ mol⁻¹, as defined by the 2019 redefinition of SI units.
Use the formula: moles = mass (g) ÷ molar mass (g/mol).
Numerically, yes — molar mass and molecular weight have the same value.
Ionic compounds like NaCl don't form discrete molecules, so technically we use 'formula mass' rather than 'molecular mass.' However, the molar mass calculation is identical: sum the atomic weights of all atoms in one formula unit.
This calculator provides molar mass values to 4 decimal places using IUPAC 2021 standard atomic weights.