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Mass Converters

Convert between mass units: grams, kilograms, milligrams, micrograms, pounds, ounces, atomic mass units (amu), and tonnes. Core to stoichiometry and analytical chemistry.

Mass is the most frequently measured quantity in chemistry. Stoichiometry calculations require converting between grams and moles, analytical chemistry works in milligrams and micrograms, and atomic-scale chemistry uses atomic mass units (amu/Da). Knowing how to convert between these scales — and between metric and imperial systems — is essential.

78 Mass Conversions

AMU to Grams Converter

g = amu × 1.66054 × 10⁻²⁴

Convert atomic mass units to grams using the factor 1 amu = 1.66054 × 10⁻²⁴ g. A unit step between atomic-scale mass and anything you can actually put on a balance.

AMU to Grams per Mole Converter

g/mol = amu × 1 (numerically identical)

The numbers are identical. A particle of mass 12 amu has a molar mass of 12 g/mol, and that equivalence is baked into the definition of the mole.

Atomic Mass Units to Kilograms Converter

kg = amu × 1.66054 × 10⁻²⁷

Convert amu to kilograms by multiplying by 1.66054 × 10⁻²⁷. Useful any time per-atom mass and SI kilograms, fixed exactly by the 2019 redefinition of Avogadro's number have to agree.

Carats to Grams Converter

g = ct × 0.2

Convert carats to grams using the exact factor 1 ct = 0.2 g. The unit bridge between gemology and any instrument that reports mass in grams.

Daltons to Grams per Mole Converter

g/mol = Da × 1

Daltons and grams per mole are the same number — a molecule of mass X Da has a molar mass of X g/mol, exactly. The conversion is the identity, but it's the bookkeeping step that lets a mass-spec readout slot directly into a stoichiometry calculation.

Daltons to Kilodaltons Converter

kDa = Da / 1000

Convert daltons to kilodaltons by dividing by 1000. The everyday step between mass-spectrometer output for peptides and the kDa scale used to talk about whole proteins.

g/mol to Kilodaltons Converter

kDa = g/mol ÷ 1000

Convert g/mol to kDa by dividing by 1000. The same molar mass in the units biochemistry actually writes — SDS-PAGE markers and MWCO filters all in kDa.

Grains to Grams Converter

g = gr × 0.06479891

Convert grains to grams by multiplying by 0.06479891. Comes up at the boundary of apothecary, ammunition, and historical pharmacopeia masses and the grams modern chemistry uses.

Grains to Milligrams Converter

mg = grains × 64.79891

Convert grains to milligrams by multiplying by 64.79891. The exact bridge from the apothecary grain to the mg scale modern dosing uses.

Grams per cm³ to Grams per Liter Density Converter

g/L = g/cm³ × 1000

Convert g/cm³ to g/L by multiplying by 1000. The clean factor that puts liquid and solid densities on the same scale as gas densities for direct comparison.

Grams per cm³ to Grams per mL Density Converter

g/mL = g/cm³ × 1 (numerically identical)

Convert g/cm³ to g/mL — numerically identical units. The identity holds because 1 cm³ equals 1 mL exactly by the definition of the liter.

Grams per cm³ to Kilograms per Liter Density Converter

kg/L = g/cm³ × 1 (numerically identical)

Convert g/cm³ to kg/L — numerically identical units. The kilo and milli prefixes cancel exactly, leaving the density unchanged in value.

Grams per cm³ to Kilograms per m³ Density Converter

kg/m³ = g/cm³ × 1000

Convert density from g/cm³ to kg/m³ by multiplying by 1000. Comes up at the boundary of chemistry-table density values and the SI base units engineering simulations expect.

Grams per cm³ to Pounds per Gallon Density Converter

lb/gal = g/cm³ × 8.34540

Density of 1 g/cm³ comes out to 8.3454 lb/US gal — also the source of the 'a US gallon of water weighs 8.34 lb' rule. The factor handles both the volume and mass conversion in one step.

Grams per Liter to Grams per cm³ Density Converter

g/cm³ = g/L / 1000

Convert g/L to g/cm³ by dividing by 1000. The clean step between gas-density and dilute-solution units (g/L) and the chemistry-table density convention (g/cm³).

Grams per mL to Grams per cm³ Density Converter

g/cm³ = g/mL × 1 (numerically identical)

g/mL and g/cm³ are the same number. The liter is defined so that 1 mL ≡ 1 cm³ exactly — the conversion is the identity, just a relabeling.

Grams per Mole to AMU Converter

amu = g/mol × 1 (numerically identical)

Convert g/mol to amu — numerically identical units. Molar mass in g/mol equals molecular or atomic mass in amu, with the equivalence built into the mole definition.

Grams per Mole to Daltons Converter

Da = g/mol × 1

Convert g/mol to Da. The two units are numerically identical, just framed differently — molar mass on one side, per-molecule mass on the other.

Grams per Second to Kilograms per Hour Converter

kg/h = g/s × 3.6

Convert g/s to kg/h by multiplying by 3.6. The factor falls cleanly out of 3600 seconds per hour over 1000 grams per kilogram.

Grams to Atomic Mass Units Converter

amu = g × 6.02214 × 10²³

Convert grams to atomic mass units by multiplying by Avogadro's number. A scale jump of twenty-four orders of magnitude — from bench measurements down to per-particle atomic mass.

Grams to Carats Converter

ct = g × 5

Convert grams to carats by multiplying by 5. The reverse of the gemological unit conversion, useful when a specimen mass recorded on a balance needs to match gemstone-industry reporting.

Grams to Grains Converter

gr = g × 15.4324

Convert grams to grains by multiplying by 15.4324. A unit step between modern gram measurements into the apothecary or ammunition-reloading grain.

Grams to Kilograms Converter

kg = g ÷ 1000

Divide grams by 1000 for kilograms. Trivial arithmetic, but it's the step that flips a bench weighing into the units a process-chemistry report uses — and a quiet cue that the scale of the problem has changed.

Grams to Micrograms Converter

µg = g × 1000000

Convert grams to micrograms by multiplying by 10⁶. The factor of a million between bench-weighing scales and the trace-analysis quantities most analytical methods detect.

Grams to Milligrams Converter

mg = g × 1000

Convert grams to milligrams by multiplying by 1000. The scale-down step that takes a gram-scale inventory quantity into the milligram-scale precision a balance actually reads.

Grams to Nanograms Converter

ng = g × 10⁹

Convert grams to nanograms by multiplying by 10⁹. The bridge across nine orders of magnitude between bench-weighing scales and the trace-analyte masses modern analytical methods detect.

Grams to Ounces Converter

oz = g / 28.3495

Convert grams to ounces by dividing by 28.3495. The step that turns a lab-scale mass in grams into the ounce units US retail labels and consumer-facing reports use.

Grams to Pennyweights Mass Converter

dwt = g × 0.643015

Convert grams to pennyweights by multiplying by 0.643015. Comes up at the boundary of balance-weighed gram mass into the pennyweight units precious-metal assay reports use.

Grams to Pounds Converter

lb = g / 453.592

Convert grams to pounds by dividing by 453.592. Useful any time bench-scale gram weights and the lb units US shipping, bulk supply, and pilot-scale work use have to agree.

Grams to Tonnes Converter

t = g / 1000000

Convert grams to metric tonnes by dividing by 10⁶. The bridge across six orders of magnitude between bench-scale weighings and industrial production figures.

Grams to Troy Ounces Mass Converter

oz t = g × 0.032151

Convert grams to troy ounces by multiplying by 0.032151. Comes up at the boundary of balance-weighed precious-metal mass to the troy-ounce units precious-metal pricing runs in.

Kilodaltons to Daltons Converter

Da = kDa × 1000

Convert kilodaltons to daltons by multiplying by 1000. The decimal step that takes a textbook protein-scale figure into the per-Da resolution of an intact-mass spectrum.

Kilodaltons to g/mol Converter

g/mol = kDa × 1000

Convert kilodaltons to g/mol by multiplying by 1000. Comes up at the boundary of biochemistry's kDa convention into the g/mol form a molarity calculation needs.

Kilograms per Hour to Grams per Second Converter

g/s = kg/h ÷ 3.6

Convert kg/h to g/s by dividing by 3.6. The factor falls cleanly out of 3600 seconds per hour over 1000 grams per kilogram.

Kilograms per Liter to Grams per cm³ Density Converter

g/cm³ = kg/L × 1 (numerically identical)

Convert kg/L to g/cm³ — numerically identical units. The kilo and milli prefixes cancel exactly, leaving the density value unchanged.

Kilograms per m³ to Grams per cm³ Density Converter

g/cm³ = kg/m³ / 1000

Convert density from kg/m³ to g/cm³ by dividing by 1000. Used at the handoff between SI engineering values and the g/cm³ density numbers chemistry tables actually use.

Kilograms to Atomic Mass Units Converter

amu = kg × 6.02214 × 10²⁶

Convert kilograms to atomic mass units by multiplying by 6.02214 × 10²⁶. Useful any time macroscopic SI mass and the u-scale used at the molecular level have to agree.

Kilograms to Grams Converter

g = kg × 1000

Convert kilograms to grams by multiplying by 1000. The step that takes a bulk or process-scale quantity down to the gram-scale numbers chemistry calculations work in.

Kilograms to Micrograms Converter

µg = kg × 10⁹

Convert kilograms to micrograms by multiplying by 10⁹. Nine prefix decades sit between bulk reagent stocks and trace-analyte detection limits.

Kilograms to Milligrams Converter

mg = kg × 1000000

Convert kilograms to milligrams by multiplying by 1,000,000. The factor of a million between bulk-reagent quantities in kg and the mg doses pharmacy and analytical chemistry actually work in.

Kilograms to Ounces Converter

oz = kg × 35.274

Convert kilograms to avoirdupois ounces by multiplying by 35.274. Used at the handoff between metric reagent labels to legacy US-imperial stockroom records.

Kilograms to Pounds Converter

lb = kg × 2.20462

Convert kilograms to pounds by multiplying by 2.20462. The step that bridges metric chemistry quantities with US-customary manufacturing and shipping units.

Kilograms to Stones Mass Converter

st = kg × 0.157473

Convert kilograms to stones by multiplying by 0.157473. Useful any time SI body-weight figures and the stones a UK participant reports back informally have to agree.

Kilograms to Tonnes Converter

t = kg / 1000

Convert kilograms to metric tonnes by dividing by 1000. The arithmetic step between bench- and pilot-scale weights and the tonne quantities industrial chemistry uses for production reporting.

Micrograms to Grams Converter

g = µg / 1000000

Convert micrograms to grams by dividing by 1,000,000. The step that takes trace-level analytical results or small biochemistry samples back into the mass unit mole calculations expect.

Micrograms to Kilograms Converter

kg = µg × 10⁻⁹

Convert micrograms to kilograms by multiplying by 10⁻⁹. A nine-decade SI prefix jump between trace-analyte detection floors and bulk reagent batches.

Micrograms to Milligrams Converter

mg = µg / 1000

Convert micrograms to milligrams by dividing by 1000. Used at the handoff between trace-analytical readings and the working unit of bench chemistry.

Micrograms to Nanograms Converter

ng = µg × 1000

Convert micrograms to nanograms by multiplying by 1000. The decimal step bridging primary calibration stocks and the ng-scale clinical assay readouts.

Milligrams to Grains Converter

grains = mg × 0.015432

Convert milligrams to grains by multiplying by 0.015432. A unit step between modern pharmacopoeial mg-stated tablet doses into the grain units older monographs use.

Milligrams to Grams Converter

g = mg / 1000

Convert milligrams to grams by dividing by 1000. The step that takes an analytical-balance reading into the gram-based arithmetic most chemistry calculations run.

Milligrams to Kilograms Converter

kg = mg ÷ 1000000

Convert milligrams to kilograms by multiplying by 10⁻⁶. Six prefix decades sit between analytical-balance masses and SI base mass units.

Milligrams to Micrograms Converter

µg = mg × 1000

Convert milligrams to micrograms by multiplying by 1000. The scale-down step that takes a bench quantity into the trace-analytical range.

Milligrams to Ounces Converter

oz = mg × 0.00003527

1 mg works out to 3.5274 × 10⁻⁵ avoirdupois ounces. The factor sits at the line between mg-scale formulation work and oz-stated US consumer-product labels — close to where FDA labeling rules actually live.

Milligrams to Pounds Converter

lb = mg ÷ 453592.37

Convert milligrams to pounds by dividing by 453,592.37. Useful any time mg-scale exposure data into the pound-stated US EPA reporting form have to agree.

Nanograms to Grams Converter

g = ng × 10⁻⁹

Convert nanograms to grams by multiplying by 10⁻⁹. A nine-decade SI prefix jump between trace-analytical sample masses and SI base mass units.

Nanograms to Micrograms Converter

µg = ng × 0.001

Convert nanograms to micrograms by dividing by 1000. The decimal step bridging trace-detection ng amounts and the µg scale of analytical-standard preparation.

Ounces to Grams Converter

g = oz × 28.3495

One avoirdupois ounce is 28.3495 g. The step that moves US-retail masses into the grams every chemistry calculation actually wants. Don't confuse with the troy ounce, which is 31.10 g and used for precious metals only.

Ounces to Kilograms Converter

kg = oz × 0.028350

Convert avoirdupois ounces to kilograms by multiplying by 0.02835. Used when US-customary mass measurements must meet the SI form scientific work expect.

Ounces to Milligrams Converter

mg = oz × 28349.5

Convert avoirdupois ounces to milligrams by multiplying by 28,349.5. Comes up at the boundary of US-customary product packaging into the mg precision an analytical assay uses.

Ounces to Pounds Converter

lb = oz ÷ 16

Convert ounces to pounds by dividing by 16. Exact by definition: the US customary definition of 1 lb = 16 oz.

Ounces to Tonnes Converter

tonnes = oz × 0.00002835

Convert avoirdupois ounces to metric tonnes by multiplying by 2.835 × 10⁻⁵. Useful any time per-batch lab consumption and global commodity-market tonnage have to agree.

Pennyweights to Grams Mass Converter

g = dwt × 1.55517

Convert pennyweights to grams by multiplying by 1.55517. Comes up when troy-system mass must be expressed in the gram form analytical XRF data read.

Pounds per Gallon to Grams per cm³ Density Converter

g/cm³ = lb/gal × 0.119826

Convert lb/gal to g/cm³ by multiplying by 0.119826. Comes up at the boundary of US-customary fuel and reagent density specs into the SI form ASTM density methods report.

Pounds to Grams Converter

g = lb × 453.592

Convert pounds to grams by multiplying by 453.592. Comes up at the boundary of US-customary reagent packaging into the gram-scale form gravimetric calculations expect.

Pounds to Kilograms Converter

kg = lb × 0.453592

1 lb = 0.45359237 kg, exact since 1959. The conversion shows up wherever US-spec bulk reagents (5 lb bottles, 25 lb bags, 55 lb pails) feed into kg-based metric arithmetic — and on the patient-weight side of any per-kg pharmacology problem.

Pounds to Milligrams Converter

mg = lb × 453 592.37

One pound is 453,592.37 mg, exact through the international avoirdupois pound. The factor comes up wherever US-customary regulatory caps meet mg-scale analytical readings — air-quality permits, hazmat reporting, anything written in pounds but measured by instrument in milligrams.

Pounds to Ounces Converter

oz = lb × 16

Convert pounds to ounces by multiplying by 16. Exact, since 1 lb = 16 oz in the US customary system.

Pounds to Stones Mass Converter

st = lb ÷ 14

Convert pounds to stones by dividing by 14. The factor follows directly from 1 stone = 14 pounds in the UK system.

Pounds to Tonnes Converter

tonnes = lb × 0.000453592

Convert pounds to metric tonnes by multiplying by 4.536 × 10⁻⁴. Comes up when US-customary plant-control data must be expressed in the tonnes per year form annual capacity reports read.

Short Tons to Tonnes (Metric Tons) Converter

t = short ton × 0.907185

Convert US short tons to metric tonnes by multiplying by 0.907185. Useful any time US-customary annual emission totals into the tonnes form European reporting expects have to agree.

Stones to Kilograms Mass Converter

kg = st × 6.35029

Convert stones to kilograms by multiplying by 6.35029. Needed when UK-conventional body-weight reporting crosses into the kg form pharmaceutical dosing expect.

Stones to Pounds Mass Converter

lb = st × 14

Convert stones to pounds by multiplying by 14. The stone is exactly 14 pounds by definition, so the conversion is simple integer arithmetic.

Tonnes to Grams Converter

g = t × 10⁶

Convert metric tonnes to grams by multiplying by 10⁶. A jump of six prefix decades, the gap between plant-scale production reporting and analytical-balance sample weights.

Tonnes to Kilograms Converter

kg = t × 1000

1 tonne = 1000 kg, exact through the SI kilo prefix. Trivial arithmetic, but the bridge between plant-scale annual reporting (tonnes) and per-batch process records (kilograms).

Tonnes to Ounces Converter

oz = t × 35274

Convert metric tonnes to avoirdupois ounces by multiplying by 35,274. Comes up when tonne-scale industrial production must be expressed in the oz form US retail packaging read.

Tonnes to Pounds Converter

lb = t × 2204.623

Convert metric tonnes to pounds by multiplying by 2204.623. Needed when tonne-stated industrial production crosses into the lb form US business records expect.

Tonnes to Short Tons Converter

short ton = t × 1.10231

Convert metric tonnes to US short tons by multiplying by 1.10231. Comes up when metric capacity reporting must be expressed in the short-ton form US operating units read.

Troy Ounces to Grams Mass Converter

g = oz t × 31.1035

Convert troy ounces to grams by multiplying by 31.1035. A unit step between precious-metals trading units into the gram form analytical workflows actually weigh.

Frequently Asked Questions

What is an atomic mass unit (amu)?
One atomic mass unit (amu), also called a dalton (Da), is defined as exactly 1/12 the mass of a carbon-12 atom. It equals approximately 1.66054 × 10⁻²⁴ grams. Atomic masses on the periodic table are given in amu, making it easy to convert to grams per mole since 1 amu corresponds to 1 g/mol.
Why do chemists use grams instead of kilograms?
While the SI base unit of mass is the kilogram, chemistry typically deals with quantities where grams are more practical. Molar masses are expressed in g/mol, and most lab-scale reactions involve grams or milligrams of reagents. Kilograms appear mainly in industrial-scale chemistry.
How do I convert between grams and moles?
Use the molar mass (M) of the substance: moles = grams / M, or grams = moles × M. For example, 36.03 g of water (M = 18.015 g/mol) equals 36.03 / 18.015 = 2.000 moles. Use the Molar Mass Calculator tool to find M for any compound.