Roofing squares calculator template

Free build guide: Roofing squares calculator for WordPress

This guide rebuilds the Roofing squares calculator from this site in Gravity Forms: 5 inputs, 3 live results and no submit button. Expect about 24 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:

• Squares to order
• Roof area (sq ft)
• Shingle bundles

What you need

• Gravity Forms (any license) — Calculation fields and drop-down values are in core; the slope factors live in the pitch choices.

Everything here is core Gravity Forms. No add-ons.

1. Create the form

1. Go to Forms → New Form and name it Roofing squares.
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. Roof length (ft) · Number · ID 1
Number Format 9,999.99; Default Value 40; Description “Footprint, eave to eave, including overhangs.”; Layout: half width, on the same row as its neighbour (drag the field beside it in the editor; no CSS class needed).

2. Roof width (ft) · Number · ID 2
Number Format 9,999.99; Default Value 30; Description “Footprint, including overhangs.”; Layout: half width, on the same row as its neighbour (drag the field beside it in the editor; no CSS class needed).

3. Pitch (rise per 12 in) · Drop Down · ID 3
Layout: half width, on the same row as its neighbour (drag the field beside it in the editor; no CSS class needed).

Choices (tick show values and enter each value):

• Flat — value 1
• 2/12 — value 1.0138
• 3/12 — value 1.0308
• 4/12 — value 1.0541
• 5/12 — value 1.0833
• 6/12 — value 1.118 (selected by default)
• 7/12 — value 1.1577
• 8/12 — value 1.2019
• 9/12 — value 1.25
• 10/12 — value 1.3017
• 12/12 — value 1.4142
• 14/12 — value 1.5366

4. Waste (%) · Number · ID 4
Number Format 9,999.99; Default Value 10; Description “10% for a simple gable, 15% with hips, valleys or dormers.”; Range min 0 max 50; Layout: half width, on the same row as its neighbour (drag the field beside it in the editor; no CSS class needed).

5. Bundles per square · Number · ID 5
Number Format 9,999.99; Default Value 3; Description “Three for most 3-tab and architectural shingles; check the wrapper.”.

6. Squares to order · Number · ID 6
Number Format 9,999.99; Description “A square is 100 sq ft of roof. Round up.”; Custom CSS Class (Appearance tab) fo-result; tick Enable Calculation, Rounding 1.

( ( {Length:1} * {Width:2} * {Pitch:3} ) * ( 1 + {Waste:4} / 100 ) / 100 )

7. Roof area (sq ft) · Number · ID 7
Number Format 9,999.99; Layout: half width, on the same row as its neighbour (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.

( {Length:1} * {Width:2} * {Pitch:3} )

8. Shingle bundles · Number · ID 8
Number Format 9,999.99; Description “Round up.”; Layout: half width, on the same row as its neighbour (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.

( ( {Length:1} * {Width:2} * {Pitch:3} ) * ( 1 + {Waste:4} / 100 ) / 100 ) * {Bundles per square:5}

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 colours. Without them the form still works; it just looks like your theme’s default Gravity Forms styling.

How the maths works is explained under “How it’s calculated” on the live Roofing squares calculator.