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