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Measurement Formulas
A graphical list of the formulas for measurement concepts. Print this page for reference.
See the online area calculator.

For additional formulas for common shapes and solids, try the page by page version of the formulas.


Area = Length X Width
A = lw

Perimeter = 2 X Lengths + 2 X Widths
P = 2l + 2w
Area = Base X Height
a = bh
Area = 1/2 of the base X the height
a = 1/2 bh
Perimeter = a + b + c
(add the length of the three sides)

Perimeter = area + b1 + b2 + c
P = a + b1 + b2 + c
Circle Try the Online tool.
The distance around the circle is a circumference. The distance across the circle is the diameter (d). The radius (r) is the distance from the center to a point on the circle. (Pi = 3.14) More about circles.
d = 2r
c = pd = 2 pr
A = pr2
Rectangular Solid
Volume = Length X Width X Height
V = lwh
Surface = 2lw + 2lh + 2wh
Volume = Base X Height
Surface = 2b + Ph (b is the area of the base P is the perimeter of the base)
Volume = pr2 x height
V = pr2 h
Surface = 2p radius x height
S = 2prh + 2pr2
V = 1/3 bh
b is the area of the base
Surface Area: Add the area of the base to the sum of the areas of all of the triangular faces. The areas of the triangular faces will have different formulas for different shaped bases.
Volume = 1/3 pr2 x height
V= 1/3 pr2h
Surface = pr2 + prs
S = pr2 + prs
pr2 + pr
Volume = 4/3 pr3
V = 4/3 pr3
Surface = 4pr2
S = 4pr2
Many assessments and tests are now allowing the use of formula cheat sheets as opposed to having to memorize the formulas. Before taking any test, be sure to ask if a formula cheat sheet is allowed. If so, print this one for a handy reference. Otherwise, with some practice using each of the formulas, you'll soon commit them to memory.

Related Links:

Geometry Tutorials

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