Lease vs. buy calculator template

Free build guide: Lease vs. buy calculator for WordPress

This guide rebuilds the Lease vs. buy calculator from this site in Gravity Forms: 8 inputs, 6 live results and no submit button. Expect about 42 minutes by hand. The template above is the same form as an import file, and the bundle adds a PDF version of this guide with a screenshot of every setting, plus the stylesheet.

You will end up with:

• Net cost of buying over the lease term
• Cost of leasing
• Buying minus leasing
• Loan payment
• Loan balance at the end of the lease term
• Equity at that point

What you need

• Gravity Forms (any license) — Calculation fields are in core; the exponents and if blocks need GP Advanced Calculations.
• GP Advanced Calculations (Gravity Wiz) — Exponents, functions and date math in calculation fields. The formulas in this template use its syntax. Part of Gravity Perks; needs the Spellbook plugin active as well.

The formulas below use GP Advanced Calculations syntax: exponents, functions or date math that core calculation fields cannot do. Install and activate it, with its Spellbook parent plugin, before you start; without it every result shows 0.

1. Create the form

1. Go to Forms → New Form and name it Lease vs. buy.
2. In Form Settings → Form Layout, set the CSS Class Name to fo-live-only. Step 3 uses it to hide the submit button.
3. Leave the form open in the editor; the fields come next.

2. Add the fields, in this order

Field IDs are assigned as you add fields. If yours come out differently, change the {Label:ID} references in the formulas to match your IDs. Settings not mentioned stay at their defaults.

1. Lease: due at signing · Number · ID 1
Number Format Currency; Default Value 2000; Description “Down payment, first month, fees.”; Layout: half width, on the same row as its neighbor (drag the field beside it in the editor; no CSS class needed).

2. Lease: monthly payment · Number · ID 2
Number Format Currency; Default Value 450; Description “With tax.”; Layout: half width, on the same row as its neighbor (drag the field beside it in the editor; no CSS class needed).

3. Lease term (months) · Number · ID 3
Number Format 9,999.99; Default Value 36; Description “The comparison runs over these months.”.

4. Buy: price · Number · ID 4
Number Format Currency; Default Value 35000; Description “Negotiated price with tax and fees.”; Layout: half width, on the same row as its neighbor (drag the field beside it in the editor; no CSS class needed).

5. Buy: down payment · Number · ID 5
Number Format Currency; Default Value 5000; Layout: half width, on the same row as its neighbor (drag the field beside it in the editor; no CSS class needed).

6. Loan APR (%) · Number · ID 6
Number Format 9,999.99; Default Value 6.5; Layout: half width, on the same row as its neighbor (drag the field beside it in the editor; no CSS class needed).

7. Loan term (months) · Number · ID 7
Number Format 9,999.99; Default Value 60; Layout: half width, on the same row as its neighbor (drag the field beside it in the editor; no CSS class needed).

8. Car value at the end of the lease term (% of price) · Number · ID 8
Number Format 9,999.99; Default Value 55; Description “What it would sell for then. 50–60% after three years is typical; the lease contract's residual is a good guide.”.

9. Net cost of buying over the lease term · Number · ID 9
Number Format Currency; Description “Down payment and loan payments, less the equity you hold at the end (car value minus what you still owe).”; Custom CSS Class (Appearance tab) fo-result; tick Enable Calculation, Rounding 0.

if( {APR:6} == 0 ):
( {Buy down:5} + ( ( {Price:4} - {Buy down:5} ) / {Loan term:7} ) * {Lease term:3} - ( ( {Price:4} * {Residual:8} / 100 ) - ( ( {Price:4} - {Buy down:5} ) - ( ( {Price:4} - {Buy down:5} ) / {Loan term:7} ) * {Lease term:3} ) ) )
else:
( {Buy down:5} + ( ( {Price:4} - {Buy down:5} ) * ( {APR:6} / 1200 ) / ( 1 - ( 1 + ( {APR:6} / 1200 ) ) ^ ( 0 - {Loan term:7} ) ) ) * {Lease term:3} - ( ( {Price:4} * {Residual:8} / 100 ) - ( ( {Price:4} - {Buy down:5} ) * ( ( 1 + ( {APR:6} / 1200 ) ) ^ {Lease term:3} ) - ( ( {Price:4} - {Buy down:5} ) * ( {APR:6} / 1200 ) / ( 1 - ( 1 + ( {APR:6} / 1200 ) ) ^ ( 0 - {Loan term:7} ) ) ) * ( ( ( 1 + ( {APR:6} / 1200 ) ) ^ {Lease term:3} ) - 1 ) / ( {APR:6} / 1200 ) ) ) )
endif;

10. Cost of leasing · Number · ID 10
Number Format Currency; Description “Everything paid over the term; you hand the car back.”; Layout: half width, on the same row as its neighbor (drag the field beside it in the editor; no CSS class needed); Custom CSS Class (Appearance tab) fo-result fo-result--sub; tick Enable Calculation, Rounding 0.

( {Lease down:1} + {Lease payment:2} * {Lease term:3} )

11. Buying minus leasing · Number · ID 11
Number Format Currency; Description “Negative means buying is cheaper over the term once you count the equity.”; Layout: half width, on the same row as its neighbor (drag the field beside it in the editor; no CSS class needed); Custom CSS Class (Appearance tab) fo-result fo-result--sub; tick Enable Calculation, Rounding 0.

if( {APR:6} == 0 ):
( {Buy down:5} + ( ( {Price:4} - {Buy down:5} ) / {Loan term:7} ) * {Lease term:3} - ( ( {Price:4} * {Residual:8} / 100 ) - ( ( {Price:4} - {Buy down:5} ) - ( ( {Price:4} - {Buy down:5} ) / {Loan term:7} ) * {Lease term:3} ) ) ) - ( {Lease down:1} + {Lease payment:2} * {Lease term:3} )
else:
( {Buy down:5} + ( ( {Price:4} - {Buy down:5} ) * ( {APR:6} / 1200 ) / ( 1 - ( 1 + ( {APR:6} / 1200 ) ) ^ ( 0 - {Loan term:7} ) ) ) * {Lease term:3} - ( ( {Price:4} * {Residual:8} / 100 ) - ( ( {Price:4} - {Buy down:5} ) * ( ( 1 + ( {APR:6} / 1200 ) ) ^ {Lease term:3} ) - ( ( {Price:4} - {Buy down:5} ) * ( {APR:6} / 1200 ) / ( 1 - ( 1 + ( {APR:6} / 1200 ) ) ^ ( 0 - {Loan term:7} ) ) ) * ( ( ( 1 + ( {APR:6} / 1200 ) ) ^ {Lease term:3} ) - 1 ) / ( {APR:6} / 1200 ) ) ) ) - ( {Lease down:1} + {Lease payment:2} * {Lease term:3} )
endif;

12. Loan payment · Number · ID 12
Number Format Currency; Layout: half width, on the same row as its neighbor (drag the field beside it in the editor; no CSS class needed); Custom CSS Class (Appearance tab) fo-result fo-result--sub; tick Enable Calculation, Rounding 2.

if( {APR:6} == 0 ):
( ( {Price:4} - {Buy down:5} ) / {Loan term:7} )
else:
( ( {Price:4} - {Buy down:5} ) * ( {APR:6} / 1200 ) / ( 1 - ( 1 + ( {APR:6} / 1200 ) ) ^ ( 0 - {Loan term:7} ) ) )
endif;

13. Loan balance at the end of the lease term · Number · ID 13
Number Format Currency; Layout: half width, on the same row as its neighbor (drag the field beside it in the editor; no CSS class needed); Custom CSS Class (Appearance tab) fo-result fo-result--sub; tick Enable Calculation, Rounding 0.

if( {APR:6} == 0 ):
( ( {Price:4} - {Buy down:5} ) - ( ( {Price:4} - {Buy down:5} ) / {Loan term:7} ) * {Lease term:3} )
else:
( ( {Price:4} - {Buy down:5} ) * ( ( 1 + ( {APR:6} / 1200 ) ) ^ {Lease term:3} ) - ( ( {Price:4} - {Buy down:5} ) * ( {APR:6} / 1200 ) / ( 1 - ( 1 + ( {APR:6} / 1200 ) ) ^ ( 0 - {Loan term:7} ) ) ) * ( ( ( 1 + ( {APR:6} / 1200 ) ) ^ {Lease term:3} ) - 1 ) / ( {APR:6} / 1200 ) )
endif;

14. Equity at that point · Number · ID 14
Number Format Currency; Description “Car value less the balance. Negative means you would owe more than it is worth.”; Custom CSS Class (Appearance tab) fo-result fo-result--sub; tick Enable Calculation, Rounding 0.

if( {APR:6} == 0 ):
( {Price:4} * {Residual:8} / 100 ) - ( ( {Price:4} - {Buy down:5} ) - ( ( {Price:4} - {Buy down:5} ) / {Loan term:7} ) * {Lease term:3} )
else:
( {Price:4} * {Residual:8} / 100 ) - ( ( {Price:4} - {Buy down:5} ) * ( ( 1 + ( {APR:6} / 1200 ) ) ^ {Lease term:3} ) - ( ( {Price:4} - {Buy down:5} ) * ( {APR:6} / 1200 ) / ( 1 - ( 1 + ( {APR:6} / 1200 ) ) ^ ( 0 - {Loan term:7} ) ) ) * ( ( ( 1 + ( {APR:6} / 1200 ) ) ^ {Lease term:3} ) - 1 ) / ( {APR:6} / 1200 ) )
endif;

3. Hide the submit button

The results are live, so nothing needs submitting. Add this filter to your theme’s functions.php or a code-snippets plugin; it hides the button on any form carrying the fo-live-only class:

add_filter( 'gform_submit_button', function ( $button, $form ) {
	return str_contains( (string) rgar( $form, 'cssClass' ), 'fo-live-only' ) ? '' : $button;
}, 10, 2 );

Or with CSS alone: .fo-live-only_wrapper .gform_footer { display: none; }

4. Put it on a page and make it look like this

Add the form to any page with the Gravity Forms block, or the shortcode [gravityform id="X" title="false" ajax="false"]. The form inherits your theme’s styles; the classes you set in step 2 are hooks for the look you see on this site:

• fo-result on a calculation field makes it the big teal result panel.
• fo-result fo-result--sub makes the smaller secondary figures.
• fo-segmented on a radio field turns it into a segmented switch.
• Two fields on one row is the editor’s own column layout: drag a field beside another and the row splits in half. No CSS class is needed, and the old gf_left_half Ready Classes are deprecated.

The bundle includes the two stylesheets that implement those classes, with notes on matching your brand colors. Without them the form still works; it just looks like your theme’s default Gravity Forms styling.

How the math works is explained under “How it’s calculated” on the live Lease vs. buy calculator.