Johnson Level & Tool CALC-1500 User manual
Instruction Manual
CALC-1500
Building Calculator
2 © 2023 Johnson Level & Tool
Building Calculator
Product Features
• Pre-programmed right angle and stair calculations including
pitch, rise and run
• Accurate stair, rafter, roof and framing calculations
• Easily calculate linear, area and volume
• Durable protective case for construction environments
• Complete rafter, circular, rake wall and board feet calculations
© 2023 Johnson Level & Tool 3
Table of Contents
Building Calculator.....................................2
Key Descriptions.......................................5
Calculator Function Keys...................................... 5
Length Keys ................................................6
Arc/Circle Keys ...............................................7
Right Triangle/Roof Framing Keys...............................7
Stair Layout Keys............................................ 9
Stair Default Values..........................................9
Stair Settings ...............................................10
Additional Functions.........................................11
User Settings ...............................................13
Using the Memory...........................................15
Basic Functions....................................... 16
Entering Dimensions.........................................16
Basic Math Operations .......................................16
Adding and Subtracting Dimensions ...........................17
Multiplying Dimensions ......................................17
Dividing Dimensions.........................................18
Calculating Percentages ......................................18
Calculating Square Area ......................................19
Calculating Rectangular Area and Volume.......................19
Adding a Waste Allowance to Squared and Cubic Units...........20
Converting Weight .........................................20
Converting Length Measurements .............................21
Converting Area Measurement ............................... 22
Sample Project Calculations ............................. 23
Board Feet and Cost .........................................23
Carpentry: Calculating Number of Studs ........................23
Baluster Spacing ........................................... 24
4 © 2023 Johnson Level & Tool
Table of Contents
Circle Area and Circumference................................ 25
Arc Angle or Degree ........................................ 25
Concrete Volume for Driveway ............................... 26
Concrete Columns .......................................... 26
Complex Concrete Volume ....................................27
Right Angle/Framing ....................................... 28
Squaring-Up a Foundation .................................. 29
Pitch — Converting Roof Angle .............................. 29
Converting Slope ........................................... 30
Common Rafter Length ....................................30
Regular Hip/Valley and Jack Rafters............................31
Irregular Hip/Valley..........................................33
Rake-Wall — With Base ..................................... 34
Stairs..................................................... 36
Stairs — Given Rise and Run ..................................37
Stairs — Given Only the Floor-to-Floor Rise; Entering Other Than
7-1/2 Inch ................................................. 38
Appendix ...........................................39
Default Settings............................................ 39
Setting Custom Fractional Resolution..........................40
Display Capacity and Errors ...................................41
Auto-Shut off...............................................41
Battery ................................................... 42
Replacing the Battery....................................... 42
Reset..................................................... 42
Area and Volume .....................................43
Area...................................................... 43
Volume ...................................................44
© 2023 Johnson Level & Tool 5
Key Descriptions
CALCULATOR FUNCTION KEYS
Off O Key: Turns all power off, clearing all non-permanent
registers.
On/C On/Clear Key: Turns power on. Pressing once clears the
display. Pressing twice clears all temporary values.
+ −×Arithmetic operation keys.
÷=
0– 9and •Keys used for entering numbers.
%Percent Key: Four-function (+, –, x, ÷) percent key.
√x Square Root Key: Used to find the Square Root of a
non-dimensional or area value.
/Fraction Bar Key: Used to enter fractions. Fractions can be
entered as proper (1/2, 1/8, 1/16) or improper (3/2, 9/8). If the
denominator (bottom value) is not entered, the calculator’s
fractional accuracy setting is automatically used.
Conv Convert Key: Used with the dimensional keys to convert
between dimensions or with other keys to access special
functions.
M+ Memory Key: Adds the displayed value to Memory. Clears
when the calculator is shut off.
Rcl Recall Key: Used with other keys to recall stored values and
settings.
6 © 2023 Johnson Level & Tool
Key Descriptions
LENGTH KEYS
Yds Yards Key: Enters or converts to yards.
Feet Feet Key: Enters or converts to feet as whole or decimal
numbers. Also used with the Inch and /keys for entering
feet-inch values. (e.g. InchFeet /
69 1 2 )
Repeated presses during conversions toggles between
fractional and decimal feet.
Inch Inch Key: Enters or converts to inches as whole or decimal
numbers. Also used with the /key for entering fractional
inch values. (e.g. Inch /
9 1 2 ) Repeated presses
during conversions toggles between fractional and decimal
inches.
mMeters Key: Enters or converts to meters.
cm Centimeters Key: Enters or converts to centimeters.
mm Millimeters Key: Enters or converts to millimeters.
Bd Ft Board Feet (Bd Ft): Enters or converts cubic values to
board feet. One board foot is equal to 144 cubic inches.
Weight Weight Key: Enters or converts (a volume value) to tons,
pounds, metric tons or kilograms. Repeated presses will
cycle through these units.
© 2023 Johnson Level & Tool 7
Key Descriptions
ARC/CIRCLE KEYS
Circ Circle Key: Calculates circle area and circumference based on
entered diameter.
CircConv Arc: Calculates arc length or degree based on
entered diameter and arc degree or length (e.g., if
arc degree is entered, it will calculate arc length, and
vice versa).
RIGHT TRIANGLE/ROOF FRAMING KEYS
Pitch Pitch Key: This key is used to enter or calculate the pitch
(slope) of a roof (or right triangle). Pitch is the amount of
“rise” over 12 inches of “run.” Pitch may be entered as:
a dimension 8 Inch Pitch
an angle 3 0 Pitch
a ratio 0 • 7 5 Conv Pitch
a percentage 7 5 %Pitch
A pitch entry will remain in permanent storage until revised or reset.
A solution will be replaced by its entered value once the calculator
is cleared.
Conv Pitch Enters pitch ratio (e.g., •5 8 3 Conv Pitch ).
Rise Rise Key: Enters or calculates the rise or vertical leg (height)
of a right triangle.
Run Run Key: Enters or calculates the run or horizontal leg
(base) of a right triangle.
8 © 2023 Johnson Level & Tool
Key Descriptions
RIGHT TRIANGLE/ROOF FRAMING KEYS (continued)
Diag Diagonal Key: Enters or calculates the common or diagonal
leg (hypotenuse) of a right triangle. Typical applications are
“squaring” slabs or finding common rafter lengths.
Hip/V Hip/Valley Key: Calculates length of the regular or
irregular hip/valley rafter.
Hip/VConv Irregular Pitch: Enters irregular pitch used to
calculate lengths of the irregular hip/valley and
jack rafters.
Jack Jack Key: Calculates jack rafter lengths on the
regular-pitched roof side.
JackConv Irregular Jack: Calculates jack rafter lengths on the
irregular-pitched roof side.
R/Wall Rake-Wall Key: Finds the stud sizes based on entered
right triangle values and the stored on-center spacing.
If a dimensional value is entered before pressing R/Wall ,
that value is considered the base and will be added to
the stud lengths.
© 2023 Johnson Level & Tool 9
Key Descriptions
STAIR LAYOUT KEYS
Stair Stair Key: Given rise and/or run and entered/stored
variables, calculates or displays:
Press Result
1 Riser height
2 Number of risers
3 Riser overage/underage
4 Tread width
5 Number of treads
6 Tread overage/underage
7 Stringer length
8 Angle of incline
9 Stored run
10 Stored rise
11 Stored desired riser height
12 Stored desired tread width
STAIR DEFAULT VALUES
• 7-1/2" Desired riser height
• 10" Desired tread width
10 © 2023 Johnson Level & Tool
Key Descriptions
STAIR SETTINGS
You may set “desired riser height” and “desired tread width” to any
value by using the following keys:
Conv 7Riser Height: Stores a desired riser height other
than 7-1/2" (default). For example, enter 4 inches:
4 Inch Conv 7 .
Conv 9Tread Width: Stores a desired tread width other
than 10" (default). For example, enter 24 inches:
2 4 Inch Conv 9 .
© 2023 Johnson Level & Tool 11
Key Descriptions
ADDITIONAL FUNCTIONS
Backspace Key: Used to delete entries one keystroke at a
time (unlike the On/C function, which deletes the entire
entry).
Conv ÷(1/x) Reciprocal: Finds the reciprocal of a number.
(e.g., 8Conv ÷ 0.125).
Conv ×Clear All: Clears all values, including M+, and returns
all stored values to the default settings (does not
affect Preference Settings).
Conv −(+/-) Toggle
Conv +Pi (π): 3.141593
Conv √x x2: Squares a linear or non-dimensional value.
Conv %Preference Settings
Conv M+ Memory Minus (M-): Subtracts the displayed value
from Memory.
Conv Rcl Memory Clear: Clears Memory without changing
current display.
Rcl Rcl Memory Clear: Clears Memory and displays Memory
Total.
12 © 2023 Johnson Level & Tool
ADDITIONAL FUNCTIONS (continued)
Rcl =Paperless Tape: Useful for checking figures, as it
scrolls through your past 20 entries or calculations.
Press Rcl =to access Paperless Tape mode. Press +
or −to scroll forward or backward. Press =to exit
mode and continue with a new entry or calculation.
PaPerless TaPe examPle
Add 8 feet, 6 feet and 2 feet, then access the paperless tape mode
and scroll back through your entries. Then, back up one entry, exit
the tape mode and add 8 feet to the total.
KEYSTROKE DISPLAY
On/C On/C ........................................................ 0
8Feet +.............................................8 FEET 0 INCH
6Feet +............................................ 14 FEET 0 INCH
2Feet =............................................ 16 FEET 0 INCH
Rcl =.........................................TTL = 16 FEET 0 INCH
+...................................................01 8 FEET 0 INCH
+.................................................02 + 6 FEET 0 INCH
+.................................................03 + 2 FEET 0 INCH
−.................................................02 + 6 FEET 0 INCH
=...............................................TTL = 16 FEET 0 INCH
+ =
8Feet ........................................24 FEET 0 INCH
Key Descriptions
© 2023 Johnson Level & Tool 13
Key Descriptions
USER SETTINGS
Press Conv , then %, then keep pressing %to toggle through the
main settings. Press the + key to advance within the sub-setting.
Use the − key to reverse within the sub-setting. Press the On/C key
to exit Preferences.
PRESS Conv AND: SETTING — FUNCTION
First press of %: Fractional Resolution:
– 1/16
+ – 1/32
+ – 1/64
+ – 1/2
+ – 1/4
+ – 1/8
+ – 1/16 (repeats options)
Second press of %: Area Displays:
– Std.
+ – 0 SQ FEET
+ – 0 SQ YD
+ – 0 SQ M
+ – Std. (repeats options)
Third press of %: Volume Displays:
– Std.
+ – 0 CU YD
+ – 0 CU FEET
+ – 0 CU M
+ – Std. (repeats options)
14 © 2023 Johnson Level & Tool
USER SETTINGS (continued)
Fourth press of %: Meter Linear Displays:
– 0.000 M
+ – FLOAt M (floating point)
+ – 0.000 M (repeats options)
Fifth press of %: Decimal Degree Displays:
– 0.00º
+ – FLOAt (floating point)
+ – 0.00º (repeats options)
Sixth press of %: Fractional Mode:
– Std.
+ – COnSt
+ – Std. (repeats options)
Key Descriptions
© 2023 Johnson Level & Tool 15
Key Descriptions
USING THE MEMORY
Whenever the M+ key is pressed, the displayed value will be added
to the Memory. Other Memory functions include:
FUNCTION KEYSTROKES
Add to Memory ................................................. M+
Subtract from Memory ...................................... Conv M+
Recall Total in Memory ...................................... Rcl M+
Display/Clear Memory....................................... Rcl Rcl
Clear Memory.............................................. Conv Rcl
Memory is semi-permanent, clearing only when you:
• Turn off the calculator.
• Press Rcl Rcl
• Press Conv Rcl
• Press Conv ×(Clear All)
When Memory is recalled ( Rcl M+ ), consecutive presses of M+
will display the total, the calculated average, and the total count of
the accumulated values.
Example:
KEYSTROKE DISPLAY
445M+ ........................................... M+ 445 M
165M+ ............................................M+ 165 M
775Conv M+ .......................................M- 775 M
Rcl M+ ...................................... TTL STORED - 165 M
M+ ....................................................AVG – 55 M
M+ .......................................................CNT 3 M
Rcl Rcl .................................................M+ – 165
16 © 2023 Johnson Level & Tool
Basic Functions
ENTERING DIMENSIONS
linear Dimensions
When entering feet-inch values, enter dimensions from largest to
smallest — feet before inches, inches before fractions. Enter fractions
by entering the numerator (top number), pressing /(Fraction Bar
key) and then the denominator (bottom number).
Note: If a denominator is not entered, the fractional setting value is
used.
Examples of how linear dimensions are entered (press On/C after
each entry):
DIMENSIONS KEYSTROKE
6 yards ..................................................... 6Yds
5 feet 1-1/2 inch ............................ 5Feet 1Inch 1/2
58.5 meters .......................................... 58•5m
BASIC MATH OPERATIONS
Your calculator uses standard chaining logic, which simply means
that you enter your first value, the operator ( +, –, ×, ÷), the
second value and then the Equals sign ( =).
A. 3+2=5.
B. 3–2=1.
C. 3×2=6.
D. 3÷2=1.5
This feature also makes the calculator simple to use for dimensional
applications.
© 2023 Johnson Level & Tool 17
Basic Functions
ADDING AND SUBTRACTING DIMENSIONS
Add the following measurements:
• 6 feet 1-1/4 inches
• 15 feet 5-1/4 inches
• 16.75 inches
Then subtract 3-1/8 inches.
KEYSTROKE DISPLAY
On/C On/C ........................................................ 0
6 1 1 4
Feet Inch / + ......................... 6 FEET 1-1/4 INCH
51 5 1 4
Feet Inch / + .....................21 FEET 6-1/2 INCH
6• 71 5 Inch = .............................22 FEET 11-1/4 INCH
3 1 8
Inch /– = .............................22 FEET 8-1/8 INCH
MULTIPLYING DIMENSIONS
What is the perimeter of a room with three walls which measure
11 feet 5-1/4inches each?
KEYSTROKE DISPLAY
3 1 1 1 45
×Feet Inch / =
................34 FEET 3-3/4 INCH
Multiply 5 feet 3 inches by 11 feet 3-3/4 inches:
KEYSTROKE DISPLAY
5 113 ×
Feet FeetInch
3 3 4
Inch / =
....59.39063 SQ FEET
18 © 2023 Johnson Level & Tool
Basic Functions
DIVIDING DIMENSIONS
Divide 17 feet 7-3/4 inches into thirds (divide by 3):
KEYSTROKE DISPLAY
On/C On/C ........................................................ 0
71 7 3 4 3
Feet Inch / ÷ = ..............5 FEET 10-9/16 INCH
How many 3 feet 6 inch pieces can you cut from one 25 foot board?:
KEYSTROKE DISPLAY
On/C On/C ........................................................ 0
52 3 6
Feet Feet Inch
÷=...........................7.142857
(or 7 whole pieces)
CALCULATING PERCENTAGES
Add a 10% waste allowance to 2.78 cubic yards:
KEYSTROKE DISPLAY
On/C On/C ........................................................ 0
•2 1 07 8 Yds Yds Yds + % ................... 3.058 CU YD
What is 25% of $2,150? :
KEYSTROKE DISPLAY
On/C On/C ........................................................ 0
12 2 55 0 × % .................................... 537.50
© 2023 Johnson Level & Tool 19
Basic Functions
CALCULATING SQUARE AREA
Find the area of a square room with sides measuring
15 feet 8-1/2 inches.
KEYSTROKE DISPLAY
On/C On/C ........................................................ 0
51 8 1 2
Feet Inch / ........................ 15 FEET 8-1/2 INCH
√x
Conv (X2)........................................246.7517 SQ FEET
CALCULATING RECTANGULAR AREA AND VOLUME
Find the area and volume:
• Length: 20 feet 6-1/2 inches
• Width: 11 feet 5-1/4 inches
• Height: 8 inches
First, multiply the length times the width to find the area. Then,
multiply the area times the height to find the volume:
KEYSTROKE DISPLAY
On/C On/C ........................................................ 0
20Feet 6Inch 1/2×....................20 FEET 6-1/2 INCH
11Feet 5Inch 1/4×.....................234.9453 SQ FEET
8Inch =..........................................156.6302 CU FEET
Convert to YD:
Conv Yds .............................................5 .801119 CU YD
20 © 2023 Johnson Level & Tool
Basic Functions
ADDING A WASTE ALLOWANCE TO SQUARED AND CUBIC
UNITS
Add a 10% waste allowance to 20 square feet. Then add a 20% waste
allowance to 150 cubic feet:
KEYSTROKE DISPLAY
On/C On/C ........................................................ 0
02 1 0
Feet Feet + % ..............................22 SQ FEET
051 2 0
Feet Feet Feet + % ......................180 CU FEET
CONVERTING WEIGHT
Convert 20 pounds to other weights (tons, metric tons, kilograms):
KEYSTROKE DISPLAY
On/C On/C ........................................................ 0
20Weight Weight ..........................................20 LB
Conv Weight .......................................0.009072 MET Ton
Weight ..................................................9.071847 kG
Weight .....................................................0.01 Ton
* Calculator may not display pounds upon first press of Weight ; it
depends on which unit was accessed last. So press Weight until LB (or
desired unit) is displayed, then convert.
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