PPM Concentration Calculator

Summary

Convert ppm to mg/L, mg/kg, percent by mass, and molarity — or go the other direction — with optional molar mass input for molarity conversions.

How it works

1. Select the input unit (ppm, mg/L, mg/kg, % w/w, or molarity) from the dropdown.
2. Enter the numeric concentration value in the input field.
3. Enter the solution density (g/mL) — defaults to 1.00 g/mL for dilute aqueous solutions.
4. Optionally enter the solute molar mass (g/mol) to enable molarity conversion.
5. Click Convert to see all equivalent concentration values instantly.
6. Click any result to copy it, or use Copy All to grab all values at once.

Use cases

• Convert drinking-water contaminant limits from ppm to mg/L for regulatory compliance.
• Check nutrient solution concentrations in hydroponics or aquaculture.
• Convert food additive limits between ppm, mg/kg, and percent by mass.
• Calculate molarity from a ppm reading in environmental water quality reports.
• Cross-check reagent concentrations in analytical chemistry protocols.
• Convert soil contamination data between mg/kg and percent by mass.
• Prepare standard solutions for calibration by working backward from target ppm.
• Verify concentration consistency between lab instruments reporting different units.

Frequently Asked Questions