## Measurement Conversions

• To find circumference of circle — multiply diameter by 3.1416
• To find diameter of a circle — multiply circumference by .31831
• To find area of a circle — multiply square of diameter by .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 .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 .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 .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 on cone or pyramid equals multiply area of two ends and get square root. Add the two areas and times 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 .434
• Steam rising from water at its boiling point (212 degrees F.) has a pressure equal to the atmosphere (14.7 lbs to the square inch)
• A standard horse power: The evaporation of 30 lbs of water per hour from a feed water temperature of 100 degrees 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 .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