Convert kg/ft³ to kg/m³ Instantly
Use this Kilograms per Cubic Foot to Kilograms per Cubic Meter converter to change mass density from kg/ft³ into kg/m³ instantly. Enter any positive or zero density value, reverse the calculation, calculate density from mass and volume, or compare several common density units in one place.
Convert forward, reverse the conversion, calculate density from mass and cubic feet, or translate one density value across several common units.
Enter density in kg/ft³ to calculate the equivalent kg/m³ value plus related density units.
Decimals are supported.
Reverse the conversion by dividing kg/m³ by 35.3146667215.
Enter mass in kilograms and volume in cubic feet to calculate density in kg/ft³ and kg/m³.
Enter one density and choose its starting unit to convert it to kg/ft³, kg/m³, lb/ft³ and g/cm³.
Kilograms per cubic foot and kilograms per cubic meter are both mass-density units. They describe how many kilograms of mass are associated with a given volume. The mass unit stays the same during this conversion; only the volume unit changes from cubic feet to cubic meters.
Because one cubic meter contains approximately 35.3146667 cubic feet, a density stated per cubic foot must be multiplied by that volume ratio when it is restated per cubic meter. This is why a value such as 1 kg/ft³ becomes about 35.3147 kg/m³ even though the underlying physical density has not changed.
Example: 10 kg/ft³ × 35.3146667215 = 353.146667215 kg/m³.
Example: 1,000 kg/m³ ÷ 35.3146667215 ≈ 28.316846592 kg/ft³.
The volume relationship is especially important. The international foot is defined as exactly 0.3048 meter. Cubing both sides gives 1 ft³ = 0.028316846592 m³. Dividing 1 by that cubic-foot volume gives approximately 35.3146667215 cubic feet per cubic meter, which becomes the forward density multiplier.
Use this responsive conversion chart for common kilograms-per-cubic-foot values. On smaller screens, the table can scroll horizontally without breaking the page layout.
| kg/ft³ | kg/m³ | lb/ft³ | g/cm³ |
|---|---|---|---|
| 0.1 kg/ft³ | 3.531467 kg/m³ | 0.220462 lb/ft³ | 0.003531467 g/cm³ |
| 0.25 kg/ft³ | 8.828667 kg/m³ | 0.551156 lb/ft³ | 0.008828667 g/cm³ |
| 0.5 kg/ft³ | 17.657333 kg/m³ | 1.102311 lb/ft³ | 0.017657333 g/cm³ |
| 1 kg/ft³ | 35.314667 kg/m³ | 2.204623 lb/ft³ | 0.035314667 g/cm³ |
| 2 kg/ft³ | 70.629333 kg/m³ | 4.409245 lb/ft³ | 0.070629333 g/cm³ |
| 5 kg/ft³ | 176.573334 kg/m³ | 11.023113 lb/ft³ | 0.176573334 g/cm³ |
| 10 kg/ft³ | 353.146667 kg/m³ | 22.046226 lb/ft³ | 0.353146667 g/cm³ |
| 20 kg/ft³ | 706.293334 kg/m³ | 44.092452 lb/ft³ | 0.706293334 g/cm³ |
| 25 kg/ft³ | 882.866668 kg/m³ | 55.115566 lb/ft³ | 0.882866668 g/cm³ |
| 50 kg/ft³ | 1,765.733336 kg/m³ | 110.231131 lb/ft³ | 1.765733336 g/cm³ |
| 75 kg/ft³ | 2,648.600004 kg/m³ | 165.346697 lb/ft³ | 2.648600004 g/cm³ |
| 100 kg/ft³ | 3,531.466672 kg/m³ | 220.462262 lb/ft³ | 3.531466672 g/cm³ |
| 150 kg/ft³ | 5,297.200008 kg/m³ | 330.693393 lb/ft³ | 5.297200008 g/cm³ |
| 200 kg/ft³ | 7,062.933344 kg/m³ | 440.924524 lb/ft³ | 7.062933344 g/cm³ |
0.5 × 35.3146667215 = 17.6573334 kg/m³.
2 × 35.3146667215 = 70.6293334 kg/m³.
10 × 35.3146667215 = 353.1466672 kg/m³.
50 × 35.3146667215 = 1,765.7333361 kg/m³.
The method does not change for decimal, fractional or large values. Keep enough decimal places during intermediate calculations, then round only the final displayed answer to the precision appropriate for your data.
Density is mass divided by volume. In this conversion, kilograms remain kilograms, so the entire numerical change comes from expressing the same volume basis in a different unit. A cubic meter is considerably larger than a cubic foot. Specifically, 1 m³ contains about 35.3146667 ft³.
If a material has a density of 1 kilogram in every cubic foot, then a cubic-meter-sized volume of that same material contains about 35.3146667 of those cubic-foot portions. Therefore the same density is written as approximately 35.3146667 kg/m³.
A cubic meter contains about 35.3147 cubic feet. That volume ratio explains the density conversion factor.
A kilogram per cubic foot, written kg/ft³, expresses the number of kilograms of mass contained in or assigned to one cubic foot of volume. It mixes a metric mass unit with a foot-based volume unit. You may encounter this form in mixed-unit specifications, converted engineering data, product literature, material takeoffs or datasets assembled from both metric and U.S. customary measurements.
Because kg/ft³ is less standard than kg/m³, converting it to SI units can make technical data easier to compare with specifications, laboratory results, structural calculations and material databases that use kilograms per cubic meter.
Kilogram per cubic meter, written kg/m³, is the SI derived unit used for mass density. It tells you how many kilograms of mass correspond to one cubic meter of volume. The BIPM lists kilogram per cubic meter as the coherent SI derived unit for mass density, while NIST describes the cubic meter as the SI unit of volume.
This unit appears widely in engineering, construction, physics, fluid data, bulk materials, insulation specifications, soil information, aggregates and concrete-related calculations. It also makes metric comparisons straightforward because both mass and volume are expressed in SI units.
Density connects mass and volume. If mass is known in kilograms and volume is known in cubic feet, divide the mass by the cubic-foot volume to obtain kg/ft³. You can then multiply by 35.3146667215 to obtain kg/m³. The third calculator above performs both steps at once.
Example: 100 kg ÷ 5 ft³ = 20 kg/ft³ ≈ 706.2933344 kg/m³.
This relationship is useful when a material sample, container, batch or measured quantity has a known mass and known volume but the required reporting unit is kg/m³.
The kg/ft³ to kg/m³ conversion is useful when information crosses between mixed-unit and SI workflows. A supplier may provide one quantity in cubic feet while a design specification or calculation sheet uses cubic meters. A legacy spreadsheet may store mass in kilograms but volume in cubic feet. Converting the density avoids comparing numbers that represent the same physical property in different units.
Common contexts include concrete and aggregate data, bulk storage, soil and fill materials, insulation products, packaging, industrial materials, laboratory samples and technical documentation. Always check whether the value represents true mass density, bulk density, apparent density, dry density, wet density or another defined measurement, because unit conversion cannot resolve differences in how the original density was measured.
Both use cubic feet for volume. Only the mass unit changes. Since one kilogram is approximately 2.20462262 pounds, 1 kg/ft³ is about 2.20462262 lb/ft³.
Both are metric density units. One g/cm³ equals exactly 1,000 kg/m³, so divide kg/m³ by 1,000 to obtain g/cm³.
For kg/ft³ → kg/m³, multiply by 35.3146667. Divide only for the reverse conversion.
0.3048 converts feet to meters. Volume is cubic, so the length factor must be cubed.
Both target and source use kilograms, so the mass unit does not change.
Keep adequate precision through the calculation and round the final answer.
The cubic-foot-to-cubic-meter relationship based on the international foot is exact because 1 foot is defined as exactly 0.3048 meter. However, the decimal multiplier 35.3146667215 is normally displayed with a finite number of digits. In everyday calculators, four to six decimal places may be more than enough. Technical work may preserve more digits until the final result.
Your final precision should not imply more certainty than the original measurement. For example, if a source density is given as 12 kg/ft³ with only two significant digits, reporting a converted value with ten significant digits may suggest unrealistic measurement accuracy.
Continue with related converters such as Grams to Kilograms, Grams to Pounds, Tons to Pounds, Pounds per Cubic Foot to Kilograms per Cubic Meter, Cubic Feet to Cubic Meters and a Concrete Density Calculator. These internal tools help keep mass, volume and density units consistent across calculations.
For unit definitions and SI guidance, see the NIST SI Units – Volume resource and the BIPM SI Brochure. NIST also publishes conversion-factor guidance for translating non-SI and customary units into SI units.
Quick answers about kg/ft³, kg/m³, density formulas and cubic-volume conversion.