Formula Letters:
H= Height
L= Length
P= Perimeter
LF = Linear Feet or Lineal Feet
SF = Square Foot or Feet
CF = Cubic Foot or Feet
CY = Cubic Yards
ELEV. = Elevation
BCY = Bank Cubic Yards
CCY = Compact Cubic Yards
LCY = Loose Cubic Yards
BF = Board Foot or Feet
T”W”L’ = Thickness” x Width” x Length’
T’W’L’ = Thickness’ x Width’ x Length’
VL = Volume Loose
VC = Volume Compact
C % = Compaction Percent
CMU = Concrete Masonry Unit
OH = Overhang
To Calculate or Estimate for:
1.
Concrete:
Blk. = Block
Conc. = Concrete
LA = Length Average
T’W’L’ / 27 = Concrete C.Y .
Multiply Feet Thickness x Feet Width x Feet Length / 27 = Cubic Yards.
2.
CMU, Concrete Block : * Total CMU Wall SF / 100 x 112.5 = CMU Concrete Block Count.
112.5 Blocks per 100 Square Feet of Wall Area.
Full CMU Block Size= 8” x 8” x 16” Dressed.
*(Minus Window and Door SF)
3.
CMU, Half Concrete Block : * Total CMU Building LF / 1.334’ = Half CMU Concrete Block Count.
*(When in Window & Door Elev.)=Bldg. LF (Minus Window and Door Widths) / 1.334’=Half CMU Blk. Count
Half CMU Block Size= 4” x 8” x 16” Dressed.
4.
CMU 3/8” Joint Mortar: Total CMU Wall SF / 100 x 8.5 CF = CMU 3/8” Joint Mortar CF.
8.5 Cubic Feet of Mortar per 100 Square Feet of Wall Area.
5.
Square Foot of Wall Area: L x H = Total Square Foot Wall Area.
6.
Trapezoid Area:
7.
Masonry Cement:
A = (A + B) x H
2
.33 CF of Masonry Cement per 1 CF of CMU or Stucco Mortar.
8.
Sand: .97 CF of Sand per 1 CF of CMU or Stucco Mortar.
9.
Stucco: * Total Stucco Wall Area SF / 12 = CF Stucco Mortar
SF of Wall Area / 12 = CF of ¾” Thickness Finish Stucco (includes waste)
*(Minus Window and Door SF)
10.
Pythagoreans Theorem: A2 + B2 = C2
11.
Board Feet: T”W”L’ / 12 = BF
Multiply Inch Thickness x Inch Width x Feet Length / 12 = BF

12.
Compaction:
Volume Loose =
Compaction Calculation Example:
VL
VL =
=
VL =
VC = Volume Compact
1 - Compaction %
100
VC = 177.80803
1 – (C % )25%
100
VC = 177.80803 = 237.07737 VL
.75
13.
Plywood (a Full Sheet = 4’ x 8’ = 32 SF): Wall LF x *H / 32 = Sheet Goods Required.
*Height is measured from Base of where plywood is called from, not necessarily to the bottom of the
Sole Plate, and continues to the top of Double Top Plate.
Verify the Drawings or Blueprints for Exact Height of Plywood Wall, Top to Bottom.
14.
Drywall (a Full Sheet = 4’ x 8’ = 32 SF): Wall LF x H x *2 / *32 = Sheet Goods Required.
*Multiply by 2 if Drywall is covering both sides of the wall, verify on the Detail Section Drawings.
Generally Drywall is Measured from the Floor to Ceiling, Verify the Drawings or Blueprints.
*Divide by 32 SF if the Drywall Sheet Goods are 4’ x 8’ or
*Divide by 48 SF if the Drywall Sheet Good are 4’ x 12’
15.
Drywall Joint Compound (Drywall Mud) Calculate Amount of Sheet Goods Required or Board Count.
Sheet Goods Required or Board Count / 10 = Amount of 5 Gallon Buckets Required.
Wall LF x H x 2 / *32 / 10
*Divide by 32 SF if the Drywall Sheet Goods are 4’ x 8’ or
*Divide by 48 SF if the Drywall Sheet Good are 4’ x 12’
16.
Ton : 2000 Lbs.
17.
Trapezoid : Area = ( A + B ) x H
2
18.
Deflection: D = 1/360 Span Feet x 12 / 360 = D
Example: For 12’ Floor Span of 50 PSF = 10 Lbs. Dead Load and 40lb Live Load.
19.
12 x 12 = 144 /360 = .4 ( .4 x 16 = 6.4 or 6/16” or 3/8”)
3/8” Allowable Deflection in 12’ for 50 PSF Wood Framing Floor Joist.
Acre: 43560 SF per Acre
20.
Triangle : Area = B x H
2

21.
Slopes, Examples from Ratio to a Percentage Formula:
4 : 1 Slope 1 / 4 = .25 = .25 x 100 = 25 % Slope
12 ½ % Slope 8 : 1 Slope 1 / 8 = .125 = .125 x 100 =
20 : 1 Slope 1 / 20 = .05 = .05 x 100 = 5 % Slope
22.
Slopes, Examples from Percentage to a Ratio Formula:
25% Slope 25 = .25 = 1 = 4 = 4 : 1 Slope
100 .25
12.5 % Slope 12.5 = .125 = 1 = 8 = 8 : 1 Slope
100 .125
5% Slope 5 = .05 = 1 = 20 = 20 : 1 Slope
100 .05
Slope Calculation Examples:
To Calculate a Length of a Base with a Given Slope of 25% (or .25 or 4 : 1) and an Elevation of 3’ =
4/1 = 4 4 x 3’ Elevation = Length of Base = 12’
Or 4/1 = 4 x 3’ Elevation: = 12’ Length
To Calculate a Length of a Base with a Given Slope of 12 ½ % (or .125 or 8 : 1) and an Elevation of 3’ =
8 / 1 = 8 8 x 3’ Elevation = Length of Base = 24’
Or 4/.5 = 8 x 3’ Elevation: = 24’ Length
To Calculate any Rise or Fall in Inches or Feet, with any Given Slope Percentage (%) to a 16 th
of an Inch
5 % Slope:
48” x .05 = 2.4” =
2.4 = (2”) (and now calculate the .4) answer is 2-6/16ths reduced to 2-3/8”
.4 x 16 = 6.4 or 6/16ths
2-3/8” Rise or Fall in 48”
5 % Slope:
4’ x .05 = .2’ =
.2 = (calculate .2’) = .2 x 12 = 2.4” (now its in inches)
2.4 = (2”) (and now calculate the .4) .4 x 16 = 6.4 or 6/16ths answer is 2-6/16ths reduced to 2-3/8” 2-3/8” Rise or Fall in 48”

23.
To Calculate for Sides Sloped Ends Shored:
(A + B) x H x Length
2
To Calculate for All Sides Sloped First Find LA = Length Average:
Same method as above except multiply the Length using the Length Average, not Just the Length.
Example to Calculate the (LA) Length Average:
LA = Length Average
LA = (A + B)
2
To Calculate for All Sides Sloped using LA = Length Average:
(A + B) x H x Length Average
2

For Scale Conversion:
Any Scale / 12 (decimal inch feet) x Amount of Inches Needed
Example = ½” Scale or .5 Scale
.5 / 12 = .0416 (inch decimal feet) x 8” = .333
.333 = 8” in ½” Scale
For Scale Conversion:
Example = ¼” Scale or .25 Scale
.25 / 12 = .0208 (inch decimal feet) x 8” = .167’
.167’ = 8” in ¼ ” Scale
For MSODT:
Project Amount of Inches x Scale (.5) = Actual Line Length
Actual Inches On Center (AI) 15.25” or 16” O.C.
(AI) 15.25” / 12 = 1.270’ (inch decimal feet) x .5 Scale = .635 Line Length in .5 Scale
(AI) 16” / 12 = 1.334’ (inch decimal feet) x .5 Scale = .667 Line Length in .5 Scale
For MSODT:
Line Length / Scale (.5) x 12
.39 / .5 = 78 x 12 = 9.36” Actual Inches
.667 / .5 = 1.334 x 12 = 16.008” Actual Inches
For Scale Models:
Project Actual Feet to get Model Scale Feet:
Formula: Project Actual Feet x .5 = Scale Model Feet
Example: For Scale: = ½” (or .5) = 1’
Actual Feet = 12’ x .5 (Scale) = 6” Scale Model Feet
Actual Feet = 12’ x .25 (Scale) = 3” Scale Model Feet
Project Actual Inches to get Model Scale Inches:
Formula: Project Actual Inches / 12 x Scale = Scale Model Inch
Example: For Scale: 2” = 1’
Actual Inches / 12 x 2 (Gives Scale Size in Inches) (Remaining Decimal Multiply by 16)
Round Up .5 (Our Tolerance is 16ths) = Scale Model Inch
Actual Inches = 41” / 12 = 3.416 x 2 =6.833 Scale Size is 6” Plus Balance (.833 x 16 = 13.333)
6 and 13/16” = Scale Model Inch

Wall Framing Layout Information
Label all Studs with Their Proper Layout Term:
X = Common Stud
T = Trimmer Stud
C = Cripple Stud
Calculate R.O Widths and Heights and Fill in the Blanks.
Calculate Header Lengths in Actual Inches: (Feet / 12 Gives Actual Inches) ADD 3” To R.O For Header Length!
Convert (Actual Inches) of the Header Lengths into the Model Scale: 2” = 1’
Formula: Actual Inches / 12 x 2 (Gives Scale Size in Inches) (Remaining Decimal Multiply by 16) Round Up .5
(Our
Tolerance is 16ths)
Example: 41”Actual Inches / 12 = 3.416 x 2 =6.833 Scale Size is 6” Plus Balance (.833 x 16 = 13.333) Answer is 6 and 13/16”
Notes: Add 2” To Windows and Interior Doors Width and Height For (R.O) Rough Openings.
Add 3” To Exterior Doors Width Only For (R.O) Rough Opening, and for the Height R.O, Just Add 2”as
Interior Door R.O.
When Applicable: Add an Additional 1” To Double Door openings Width Only for the Wood “T”
Astragal Trim Piece.
ADD 3” To The R.O For The Header Length! Example: 38” R.O Plus 3” would make the Header Length
41” Long.

Formula: Board Feet = T”W”L’ / 12
Example: 2” x 10” x 16’ Piece of Framing Material:
2” x 10” x 16’ = 320 / 12
320 / 12 = 26.667 Round Up to 27 BF
Formula: Floor Joist Headers and Floor Joists:
Calculate Floor Joist Header LF x 2 ( One for Each Side of Floor Joist Header)
Calculate one Floor Joist per Spacing and ADD 1 for the end, or as: L / Spacing + 1
Example:
For a 12’ x 20’ Building:
Using 2” x 10” Framing Material, 16” On Center, will calculate as follows:
Floor Joist Headers: Use 16’ Long Material:
Floor Joist: Use 12’ Long Material:
1.
Headers:
20 LF x 2 = 40 LF of Floor Joist Header ( One for Each Side of Floor Joist Header)
40LF / 16’ Length of Header Material = 2.5 Round Up to 3 Full Lengths, 3 x 16’=
2.
Floor Joists: 20 LF / 16” OC (or 1.334’) + 1 = Amount Needed.
20 LF/ 1.334’= 14.992 + 1 = 16 Floor Joists
3.
A total of 240 LF
16 Floor Joists x 12’ Long =
Total
48 LF
192 LF
240 LF
Board Feet = T”W”L’ / 12
2” x 10” x 240 LF’ = 4800 = 400 Total Board Feet
12 12
Cost Per Board Foot of 2” x 10” Material = $ .89 Per BF
$ 356.00 Total Board Feet = 400 x $ .89 =
$ 356.00 x 6% Tax = 21.36 + = $ 377.36

Formula: Board Feet = T”W”L’ / 12
Example: 2” x 4” x 10’ Piece of Framing Material:
2” x 4” x 10’ = 80 / 12
80 / 12 = 6.667 Round Up to 7 BF
Formula: Wall Plates and Wall Studs:
Calculate Wall Plate LF x 3 (One for Bottom Plate and Two for Double Top Plates)
Calculate one Wall Stud per LF or LF x 1
Example:
For a Wall: 8’ x 25’
Using 2” x 4” Framing Material, 16” On Center, will calculate as follows.
Wall Plate: Use 10’ Long Material:
Wall Stud: Use 8’ Long Material:
1.
Plate: 25 LF x 3 = 75 LF of Top and Bottom Plates
75LF / 10’ Long Plate Material = 7.5 Pc. Round Up to 8 Full Lengths, 8 x 10 ’= 80 LF
2.
Wall: 25 LF x 1 = 25 Studs x 8’ Long = 200 LF 200 LF
3.
A total of 280 LF Total 280 LF
Board Feet = T”W”L’ / 12
2” x 4” x 280’ = 2240 = 186.667 Round Up to 187 Total Board Feet
12 12
Cost Per Board Foot of 2” x 4” Material = $ .48 Per BF
Total Board Feet = 187 x $. 48 = $ 89.76
$ 89.76 x 6% Tax = 5.385 + = $ 95.145 $ 95.15

Rakes, Lookouts, Barge Rafters, Gable Studs Collar Beams.
Hip, Valley, Hip Jack, Cripple Jack Rafters .
Formula: Board Feet = T”W”L’ / 12
Example: 2” x 10” x 16’ Piece of Framing Material:
2” x 10” x 16’ = 320 / 12
320 / 12 = 26.667 Round Up to 27 BF
Formula: Ridge Board:
Calculate Ridge Board, Add LF of Building and then add Rake Dimension, for each end.
TWL / 12 for BF
Multiply Cost of BF by BF.
Formula: Length of Common Rafter:
Span / 2 = Run
Run x Length per Foot of Run, minus half thickness of Ridge Board, and the add Overhang.
Formula: Common Rafter Amount Required and BF:
Rafter Amount Required: Ridge Board Length / Rafter Spacing, 16” OC (1.334’) or 24” OC (2’) + 1
Basically, L / Spacing + 1 , just like Floor Joist.
Multiply Common Rafter Amount Required by Length of Common Rafter.
Multiply by 2 for each Run.
(for each side of the building and or Ridge Board)
You now have Total LF of Rafters for the Building.
TWL / 12 for BF
Multiply Cost of BF by BF.
Example: For a 12’ x 20’ Building, 16” Overhang, 12” Rake, 5/12 Slope:
Using 2” x 10” and 2” x 12” Framing Material, 16” On Center, will calculate as follows:
4.
Ridge Board:
Ridge Board: Use 2” x 12” x 12’ Long Material:
Calculate Ridge Board, Add LF of Building and then add Rake Dimension, for each end.
20’ + 12” + 12” = 22’
TWL / 12 for BF
2” x 12” x 22’ LF / 12 = 44 BF
22 / 12 = 1.833 Round Up to 2 Full Lengths, 2 x 12’ = 24’
2” x 12” x 24’ LF / 12 = 48 BF 2” x 12” x 24’ LF / 12 = 48 BF
Multiply Cost of BF by BF.
Cost = $1.25 per BF x 48 = $60.00
5.
Common Rafter:
$60.00
Length of Common Rafter = Span 12’ / 2 = Run = 6’ x 13” = 78” Minus .75 = 77.25 + 16” OH = 93.25”
Common Rafter: Use 2” x 10” x 16’ Long Material:
93.25 / 12 = 7.770 x 2 = 15.541’ so one 16’ will make 2 rafters.
Rafter Amount Required: Ridge Board = 22’ / 1.334 + 1 = 17.491 Round up to next full piece = 18
18 x 2 for each side of building = 36 Pieces x Length of Common Rafter or in this case,
36 / 2 = 18 pieces x 16’ = 288 LF
2” x 10” x 288 LF = 5760 / 12 = 480 BF 2” x 10” x 288 LF = 5760 / 12 = 480 BF
Multiply Cost of BF by BF.
Cost = $1.10 per BF x 480 = $528.00 $528.00