What is the difference between mass concentration and parts-per notation?

Mass concentration (e.g. g/L) expresses the absolute mass of solute per unit volume. Parts-per notation (e.g. ppm, ppb) expresses a dimensionless ratio. Converting between the two requires knowing the solution density or molar mass.

Is 1 ppm the same as 1 mg/L?

For dilute aqueous solutions where density ≈ 1 g/mL, yes: 1 ppm (mass/mass) ≈ 1 mg/L. For other solvents or concentrated solutions the two differ.

What units does the Mass Concentration tab support?

g/L, mg/L, μg/L, ng/L, pg/L, kg/m³, mg/m³, μg/m³, g/mL, mg/mL, μg/mL, ng/mL, g/dL, and mg/dL.

What units does the Parts-per tab support?

Fraction (dimensionless), percent (%), per mille (‰), ppm, ppb, ppt, and ppq.

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Concentration Converter

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From

Sig. figures:

Sci notation

Gram per litre

g/L

1(input)

Milligram per litre

mg/L

1000

Microgram per litre

μg/L

1.00000e+6

Nanogram per litre

ng/L

1.00000e+9

Picogram per litre

pg/L

1.00000e+12

Kilogram per cubic metre

kg/m³

Milligram per cubic metre

mg/m³

1.00000e+6

Microgram per cubic metre

μg/m³

1.00000e+9

Gram per millilitre

g/mL

0.001

Milligram per millilitre

mg/mL

Microgram per millilitre

μg/mL

1000

Nanogram per millilitre

ng/mL

1.00000e+6

Gram per decilitre

g/dL

0.1

Milligram per decilitre

mg/dL

Hover any row to copy the value or use it as the new input.

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Convert between all common concentration units in two modes: Mass Concentration (g/L, mg/L, μg/L, ng/L, pg/L, kg/m³, mg/m³, μg/m³, g/mL, mg/mL, μg/mL, ng/mL, g/dL, mg/dL) and Parts-per Notation (fraction, %, ‰, ppm, ppb, ppt, ppq). Switch modes instantly via tabs. Choose from 3 to 12 significant figures, toggle scientific notation, swap units with one click, and copy any result to the clipboard. Real-world reference values include blood glucose, WHO drinking water limits, and aqueous ppm equivalences.

How to Use

1Select the Mass Concentration or Parts-per Notation tab
2Enter a value in the From field and choose the source unit
3Select the target unit in the To dropdown to see the instant result
4Scroll the results panel to see all unit conversions at once
5Hover any row and click Copy to copy that value to the clipboard
6Click ↕ on any row to use its value as the new input
7Adjust significant figures or toggle Sci notation for large/small values

Features

Two modes: Mass Concentration (g/L base) and Parts-per Notation (fraction base)
Mass Concentration: g/L, mg/L, μg/L, ng/L, pg/L, kg/m³, g/mL, mg/mL, μg/mL, ng/mL, g/dL, mg/dL
Parts-per: fraction, %, ‰, ppm, ppb, ppt, ppq
Instant two-way conversion with From/To selectors and swap button
3–12 significant figures and scientific notation toggle
Copy any result with one click or click ↕ to use as new input
Reference panel with aqueous equivalences, blood glucose, WHO limits
100% browser-based - no data sent to any server

Concentration Converter

How to Use

Features

Frequently Asked Questions

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