Let’s assume that you have the salary calculator ready with you. It can be on a spreadsheet or in a table format as shown below:
Earnings 
Monthly 
Yearly 
Basic 
150000 
1800000 
HRA 
60000 
720000 
Travel reimbursement (LTA) 
12500 
150000 
Special allowance 
150700 
1808400 
Subtotal(A) 
373200 
4478400 
PFEmployer 
1800 
21600 
Deductions 
Monthly 
Yearly 
PF employee 
1800 
21600 
Total deductions(B) 
1800 
21600 
Total(AB) 
371400 
4456800 
Total Cost to Company 
375000 
4500000 
As per the company policies, the weightage for Basic, HRA, LTA, etc., can differ. Let's consider the weightage as provided below:
Earnings 
Monthly 
Yearly 
Comments 
Basic 
150000 
1800000 
40% of CTC 
HRA 
60000 
720000 
16% of CTC/40% of Basic 
Travel reimbursement(LTA) 
12500 
150000 
6.67% of CTC/1,50,000 whichever is lower 
Special allowance 
150700 
1808400 
Every other salary component will be considered here 
Subtotal(A) 
373200 
4478400 

PFEmployer 
1800 
21600 

Deductions 
Monthly 
Yearly 

PF employee 
1800 
21600 

Total deductions(B) 
1800 
21600 

Total(AB) 
371400 
4456800 

Total Cost to Company 
375000 
4500000 
Note: If you have a fixed value for any fields, you can declare the placeholder as a formula field. While creating them, against the Mathematical Formula field, enter the value.
Declare all the parameters on the salary calculator as form fields.

Navigate to the Settings > General Configuration > Offer Configuration > Form Fields and create all the form fields as required.

Fill in the required details in the following popup.
Use the table below to understand how to declare a form field, decide on its type and associate a formula to it.
*The below table is only for reference and may not be a realtime scenario.
Form Field Description 
Placeholder 
Type 
Formula 
Basic (Yearly) 
{{basic_y}} 
Formula 
Math.round(ctc_y*0.4) 
HRA (Yearly) 
{{hra_y}} 
Formula 
Math.round(ctc_y*0.16) 
LTA (Yearly) 
{{lta_y}} 
Formula 
Math.round(if((0.067*ctc_y)<150000,(0.067*ctc_y),150000) 
Special Allowance (Yearly) 
{{special_allowance_y}} 
Formula 
Math.round(sub_total_y  (basic_y + hra_y + lta_y)) 
Sub Total (Yearly) 
{{sub_total_y}} 
Formula 
Math.round(ctc_y  pf_y) 
PF Employer (Yearly) 
{{pf_employer_y}} 
Number 
NA 
PF Employee (Yearly) 
{{pf_employee_y}} 
Number 
NA 
Total Deductions (Yearly) 
{{total_deductions_y}} 
Number 
NA 
Total (Yearly) 
{{total_y}} 
Formula 
Math.round(sub_total_y  total_ded_y) 
CTC (Yearly) 
{{ctc_y}} 
Number 
NA 
The placeholders can be named however you want. The above names are just for reference. However, it is advised to keep it short and mention if it points to annual or monthly amounts using abbreviations: _y or _m or _annual or _monthly etc.
Note:
1. You must enter values for all fields except the formula field.
2. The formula type fields will be autopopulated with the final value on the offer letter as per the associated formula.
Learn more: Getting Started with Offer Configuration