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Performing calculations using formulas
Performing calculations using formulas
Updated over 2 weeks ago

To perform calculations using formulas, you need to use Variables

Example 1: Tax calculations

In this example, we need calculate:

  • Subtotal - Based on what products/services have been selected/number entered.

  • Tax - Tax amount (20% of subtotal)

  • Final total - Subtotal + Tax

Step 1 - Setting up Variables - @Subtotal, @Tax and @Finaltotal


Step 2 - Performing calculations using variables
​2a. Use a Subtotal variable to collect the values of what items have been selected/number entered.
2b. Add the final subtotal to the Tax variable
2c Multiply the tax variable by 0.20 to calculate the tax (e.g. 20% tax)
2d. Add the subtotal and tax to Finaltotal

Step 3 - Use Recall (@) on page to show Subtotal, Tax and Finaltotal

Step 1 - Setting up Variables - @Subtotal, @Tax and @Finaltotal

Step 2 - Performing calculations using variables

Step 3 - Use Recall (@) on page to show Subtotal, Tax and Finaltotal

Below, you can try out the above form we built:

Tax calculations - https://getformly.app/JXSoKq

Tip! - You can also import above template in your account to check the calculations and how to setup variables.



​Example 2: Wall paper - Quantity and Cost calculator

In this example, we need calculate:

  • Number of rolls needed - Based on Area to cover (Width * Height)

  • Total price ($) - Number of rolls needed * 20

Assumptions:

- one wall paper roll covers 5 m²

- one wall paper roll costs - $20

Step 1 - Setting up Variables - @Width, @Height, @subtotal_area, @Final_area, @Number_of_rolls_needed, @Total_price


Step 2 - Performing calculations using variables
​2a. Use a Width and Height variable to calculate Final area to cover: (Width * Height) m²
2b. Number of rolls needed: Area to cover/5
2c Total price ($): Number of rolls needed * 20

Step 3 - Use Recall (@) on page to show Final Area to cover, Number of rolls needed and Total price


Step 1 - Setting up Variables - @Width, @Height, @subtotal_area, @Final_area, @Number_of_rolls_needed, @Total_price

Step 2 - Performing calculations using variables

Step 3 - Use Recall (@) on page to show Total area to cover, Number of rolls needed and Total price.

Below, you can try out the above form we built:

Wall paper: Quantity and Cost calculator - https://getformly.app/gProD2

Tip! - You can also import above template in your account to check the calculations and how to setup variables.


Example 3: Show values as percentages

The quiz tests knowledge of 3 topics - Science, Math and Geography.

Scoring:

  • Each topic (Science, Math, and Geography) has 3 questions.

  • Total score for each topic is out of 3.

  • Maximum overall score: 9 points.

For each correct answer: +1 point

Step 1 - Setting up Variables - @Science, @Math, @Geography, @Total_score


Step 2 - Performing calculations using variables

​2a. Use a topic variable to collect the values for respective topic questions. The value of the variable increases by 1 point only when a respondent answers a question correctly in that topic.

For each correct answer: +1 point

2b. Always add individual topic score to Total score.


2c. This below rule will convert your variable’s value at the end of the quiz into a percentage-friendly format.

  • Add a rule so that the variable’s value is always divided by the total number of questions.

  • Also, Add a rule so that the variable’s value is always multiplied by 100.

Always Divide @Science by 3

Always Mulitply @Science by 100

Always Divide @Math by 3
Always Mulitply @Math by 100

Always Divide @Geography by 3
Always Multiply @Geography by 100

Always Divide @Total_score by 9

Always Multiply @Total_score by 100


Step 3 - Use Recall (@) on page to show individual topic score (Science, Math and Geography) and Total score in percentage format.

Step 1 - Setting up Variables - @Science, @Math, @Geography, @Total_score

Step 2 - Performing calculations using variables

Step 3 - Use Recall (@) on page to show individual topic score (Science, Math and Geography) and Total score in percentage format.


Type “%” to the right of the variable, to make it clear to the respondent that you’re showing them a percentage score.


Below, you can try out the above form we built:

Knowledge quiz: Show values as percentages - https://getformly.app/scsqTj

Tip! - You can also import above template in your account to check the calculations and how to setup variables.

Example 4: Field value formula

In this example, we need to calculate final value for the below formula:

Formula: ((Field A x 1.49) - (Field B x 20%) + (Field C x 0.5))

Step 1 - Setting up Variables - @A_calculations, @B_calculations, @C_calculations and @Final_total


Step 2 - Performing calculations using variables
​2a. Use @A_calculations variable to collect the value of number entered in Field A and then multiply it by 1.49
2b. Use @B_calculations variable to collect the value of number entered in Field B and then multiply by 0.2 (20%)
2c. Use @C_calculations variable to collect the value of number entered in Field C and then multiply by 0.5
2d. Add @A_calculations to @Final_total

2e. Subtract @B_calculations from @Final_total
2f. Add @C_calculations to @Final_total

Step 3 - Use Recall (@) on page to show A_calculations, B_calculations, C_calculations and Final_total

Step 1 - Setting up Variables - @A_calculations, @B_calculations, @C_calculations and @Final_total

Step 2 - Performing calculations using variables

Step 3 - Use Recall (@) on page to show A_calculations, B_calculations, C_calculations and Final_total.

Below, you can try out the above form we built:

Field value formula - https://getformly.app/e86u4B

Tip! - You can also import above template in your account to check the calculations and how to setup variables.


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