ChemEs Calculator
Practical Calculators for Modern Chemistry.
Molarity Calculator
Find mass, volume, concentration and stock dilutions.
Open toolSolution Preparation
Prepare solutions with purity correction and weighing guidance.
Open toolMoles ↔ Grams
Convert between mass and amount with explicit units.
Open toolReaction Stoichiometry
Plan equivalents, limiting reagents and isolated yields.
Open toolGlassware Guide
Explore 26 illustrated pieces of laboratory glassware.
Open toolLaboratory Setups
Review six annotated laboratory arrangements.
Open toolFree to use. Calculations stay on your device.
PLAN YOUR REACTION
Reaction stoichiometry
Plan quantities, select your reference and report your isolated yield.
Reagents
Live calculationsSelect any reagent as your 1.00-equivalent reference. Other equivalents update automatically.
Select a reference match to fill formula and MW, or enter your own values.
Density & stock concentration
Density is required for neat liquids; concentration is required for stock solutions. Either may also be supplied to calculate dispensing volumes.
3.62004 mmol · 1 eq
Select a reference match to fill formula and MW, or enter your own values.
Density & stock concentration
Density is required for neat liquids; concentration is required for stock solutions. Either may also be supplied to calculate dispensing volumes.
10.5789 mmol · 2.92232 eq
Expected product
Select a reference match to fill formula and MW, or enter your own values.
0.652187 g · 3.62004 mmol
Limiting reagent: Salicylic acid
500 mg · 3.62004 mmol · 1 eq
1080 mg · 10.5789 mmol · 2.92232 eq
1 mL neat liquid
Equations & assumptions
n = m / MW; liquid n = ρV / MW; stock n = CV. Product n = min(nᵢ / νᵢ) × νproduct. Supply balanced coefficients and the correct chemical form. Assumes pure reagents and complete conversion. Product identity and mechanism are not inferred. Uncheck catalysts, solvents and nonstoichiometric additives as appropriate.
Actual Yield & Publication Results
Only enter measured isolated material. Example data are illustrative.
Enter an actual isolated mass to calculate yield.
About ChemEs Calculator
A browser-based chemistry workbench for researchers and students. ChemEs Calculator is a provisional brand pending domain and trademark checks.
Methodology
Calculations use explicit units and supplied stoichiometric coefficients. Molecular-weight catalogue records link to PubChem; HRMS uses monoisotopic masses and stated ion corrections. Educational diagrams are original schematics, not manufacturer drawings or operating procedures. Automated tests check arithmetic and software behavior, not universal scientific correctness.
Privacy
Normal calculations, searches and formatting run locally. Experimental data are not sent to a server. Only your theme preference is saved in localStorage; calculation inputs stay in memory during the session and reset on reload. Following an external reference link connects to that external site. The installed app caches static files and a release-check timestamp for offline access, never experimental inputs. The hosting provider receives ordinary connection information, such as IP addresses and requested file paths. No analytics or tracking scripts are included.
Beta limitations
Independently verify results before experimental or publication use. Diagrams are educational references and do not replace training, equipment manuals or approved SOPs. Offline launches expire after seven days without a verified release check. An already open session is not forcibly closed; reconnect and check for updates regularly.
Contact
A public contact channel has not yet been configured. No affiliation or certification is claimed.
How it works
Equivalents compare reagent amounts with a chosen reference. For a balanced reaction, divide each included reactant’s amount by its stoichiometric coefficient; the smallest value limits the reaction extent. Multiply this extent by the product coefficient for theoretical product amount. Catalysts and solvents need not participate in limiting-reagent analysis.
Formula: n = m / MW. Theoretical product amount = min(nᵢ / νᵢ) × νproduct. Percentage yield = (actual isolated mass / theoretical product mass) × 100.
Worked example: Illustrative esterification: benzoic acid + methanol → methyl benzoate + water (1:1:1:1). 500 mg benzoic acid (MW 122.12) gives 4.094 mmol; 262.4 mg methanol (MW 32.04) gives 8.190 mmol. Benzoic acid limits the calculated maximum: 4.094 mmol methyl benzoate (MW 136.15) = 557.44 mg. An illustrative isolated mass of 450 mg gives 80.7%. This theoretical maximum assumes complete conversion; it does not predict equilibrium or experimental recovery.
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