Measurement Conversions
- To find circumference of circle — multiply diameter by 3.1416
- To find diameter of a circle — multiply circumference by 0.31831
- To find area of a circle — multiply square of diameter by 0.7854
- Area of a rectangle equals length multiplied by breadth
- Doubling the diameter of a circle increases its area four times
- To find area of a triangle — multiply base by 1/2 perpendicular height
- Area of ellipse equals product of both diameters times 0.7854
- Area of a parallelogram equals base times altitude
- To find side of an inscribed square:
- Multiply diameter by 0.7071
- Or multiply circumference by 0.2251
- Or divide circumference by 4.4428
- Side of an inscribed cube equals radius of sphere times 1.1547
- To find side of an equal square, multiply diameter by 0.8862
- Square: A side multiplied by 1.4142 equals diameter of its circumscribing circle
- A side multiplied by 4.443 equals the circumference of its circumscribing circle
- A side multiplied by 1.128 equals diameter of an equal circle
- A side multiplied by 3.547 equals circumference of an equal circle
- To find cubic inches in a ball, multiply cube of diameter by 0.5236
- To find cubic contents of a cone, multiply area of base by 1/3 the altitude
- Surface of frustrum of cone or pyramid equals sum of circumference of both ends times 1/2 slant height plus area of both ends
- Contents of frustrum of cone or pyramid equals multiply area of two ends and get square root, add the two areas and multiply by 1/3 altitude
- Doubling the diameter of a pipe increases its capacity four times
- A gallon of water (U.S. Standard) weighs 8 1/3 lbs. and contains 231 cubic inches
- A cubic foot of water contains 7 1/2 gallons, 1728 cubic inches, and weighs 62 1/2 lbs.
- To find the pressure in pounds per square inch of a column of water, multiply the height of the column in feet by 0.434
- Steam rising from water at its boiling point (212°F) has a pressure equal to the atmosphere (14.7 lbs per square inch)
- A standard horse power: The evaporation of 30 lbs of water per hour from a feed water temperature of 100°F into steam at 70 lbs gauge pressure
- To find capacity (in U.S. gallons) of tanks of any size, given dimensions of a cylinder in inches, square the diameter, multiply by the length, and by 0.0034
- To ascertain heating surface in tubular boilers, multiply 2/3 the circumference of boiler by length of boiler in inches and add it to the area of all the tubes
