Center of mass is the balance point of a group of masses. It is not always the geometric center. Heavy parts pull the center toward their locations. This matters in physics, product design, vehicles, robotics, lifting plans, and many conversion tasks. A small coordinate change can move the balance point far enough to create tilt or unsafe loading.
This calculator uses the weighted average equation. Each mass is multiplied by its coordinate. Those products are called moments. The moments are added, then divided by total mass. The same idea works for x, y, and z coordinates. When all masses are equal, the result becomes the average position. When one mass is larger, the result moves closer to that mass.
Use consistent units for best results. The form can convert grams, kilograms, pounds, and ounces into a common mass unit. It also converts meters, centimeters, millimeters, inches, and feet. The final center can be displayed in your chosen length unit. Negative coordinates are allowed, so you can work around any origin point. This helps when parts sit left, below, or behind the reference point.
For advanced checks, enter a support point. The calculator measures the offset between the support and the computed center. A larger horizontal offset means a larger tipping moment under gravity. This is useful for platforms, shelves, fixtures, and machines. The tool also reports total mass and each axis moment. These values make it easier to verify hand calculations.
The center of mass equation assumes point masses or objects reduced to their own centers. For a solid uniform shape, first find the shape center. Then use that center as a point entry with the object mass. Composite bodies can be handled by adding every part separately. Remove zero or unknown masses before trusting the result.
The example table shows simple balanced and unbalanced systems. Try the sample numbers first. Then replace them with your own measurements. Download the CSV file for spreadsheets. Download the PDF report for records. Keep the same origin for every row. Label parts clearly. Review the total mass before using the center in safety decisions. This improves accuracy and reduces repeated measurement mistakes later.