1. Select the frame condition
Choose whether you are checking a joist or bearer, then set the required span, spacing or FLW, span type, deck height and covering load.
Span design at a glance
The core inputs that change the result
Span tables are not based on length alone. The same member can pass or fail depending on load width, spacing, support condition, deck height and the dead load carried by the frame.
| Input | What it means | Why it matters |
|---|---|---|
| Bearer span | The distance between posts, walls or other bearer supports. | Longer spans generally need deeper, stronger or doubled members. |
| Joist span | The distance a joist runs between bearers or supports. | Joist span is strongly affected by joist spacing and deck loading. |
| FLW | Floor load width, or the tributary floor width carried by a member. | A larger FLW increases the load on a bearer or beam. |
| Spacing | The distance between repeated joists or framing members. | Closer spacing usually reduces the load carried by each joist. |
| Span type | Single span or continuous span over multiple supports. | Continuous spans may allow better performance, depending on the table. |
| Dead/live load | Permanent deck weight and imposed use load. | Heavier decking, higher decks or different use cases require stronger checks. |
How SpanFinder works
Calculator, then evidence, then related tools
This structure is designed to feel like a proper professional resource: the calculator answers the immediate question, then the page explains the terms and provides the next logical calculators.
2. Compare suitable matches
The results rank product groups by the smallest suitable published match first, while still allowing you to inspect larger or alternate options.
3. Save a report
Open a result, save it to the project report, adjust the inputs and save additional selections for a printable project summary.
Popular span calculators
Grouped tools, not random buttons
These links are deliberately grouped around the user’s next question: calculate the span, understand the load width, then compare products or supporting guides.
Floor joist & bearer span calculatorCompare steel, LVL and timber options for residential floor joists, bearers and single-storey wall/roof bearer cases.Open calculator →
Deck joist span calculatorCheck joist options based on required span and joist spacing.Open calculator →
Deck bearer span calculatorCompare bearer options using FLW, support condition and required span.Open calculator →
Floor load width calculatorCalculate tributary floor load width before choosing a bearer or beam.Open calculator →
Roof span calculator AustraliaComing soon: roof rafter, roof beam and framing span checks using published Australian source tables.Coming soon
Roof load width calculatorComing soon: calculate roof load width before checking rafters, roof beams and wall-bearing floor members.Coming soon
Deck joist spacing calculatorUnderstand spacing options and how they affect member selection.Open calculator →
Bearer and post spacing calculatorPlan supports and setout before finalising a bearer layout.Open calculator →
Deck span calculatorUse the broader deck span page as a starting point for framing checks.Open calculator →
Guides and span tables
Supporting content that makes the calculator easier to trust
These pages give Google and users a clearer map of the site, while helping customers understand the terminology before they use a result.
Span table resources
Product and load guides
Important: SpanFinder is a preliminary comparison tool. It does not replace engineering, certification, manufacturer documentation, NCC requirements, Australian Standards or project-specific checks such as bracing, connections, durability, corrosion exposure, footing design and site conditions.