# Span Calc — Span calculator using NDS® > Wood joist and rafter span calculator based on NDS® standards. (iPhone/iPad app by American Wood Council.) - Source: https://appshunter.io/ios/app/span-calc/id380481343 (this page in markdown: same URL + `.md`) - Developer: [American Wood Council](https://appshunter.io/developer/380481346) - Category: Utilities, Business - Price: Free - Rating: 2.87/5 from 15 App Store ratings · 27 written reviews indexed - Age rating: 17+ - Requires: iOS 14.2 · 168 MB - Languages: English - Released: 2010-07-09 - Data updated: 2026-08-13 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/span-calc/id380481343/reviews.md ## What is Span Calc? The American Wood Council (AWC) Span Calculator for Wood Joists and Rafters (Span Calc) performs calculations for all species and grades of commercially available softwood and hardwood lumber as found in the 2021 National Design Specification® (NDS®) for Wood Construction. Joists and rafter spans for common loading conditions can be determined. A span options calculator allows selection of multiple species and grades for comparison purposes. Supported by the Softwood Lumber Board. Maximum horizontal spans for joists and rafters are calculated based on the following assumptions and conditions: · Joists and rafters are oriented to support vertical loads applied to the narrow (1.5 in. thick) face of the member, resulting in strong-axis bending. · At least three joists or rafters are installed parallel to one another and spaced not more than 24 inches on-center, with properly designed sheathing attached on the top (compression) edge of each joist or rafter. · Joists and rafters are single-span with adequate structural support at each end. The Span Calculator does not address cantilevered joists and rafters, multiple-span joists and rafters, or spliced joists and rafters. · For joists and rafters, most building codes specify a minimum bearing length of 1.5 inches on wood or metal and not less than 3 inches on masonry or concrete. These minimum bearing lengths are to be used in the absence of calculated bearing lengths. Consult the local building code for specific requirements. · Joists and rafters carry only combinations of dead load plus live load (D + L), dead load plus snow load (D + S), or dead load plus roof live load (D + Lr). The Span Calculator does not address wind load or seismic load. · Buildings in regions with ground snow loads greater than 70 psf should not use the prescriptive provisions of the governing building code without approval of the authority having jurisdiction. Buildings in these high snow zones should be designed in accordance with accepted engineering practice. While every effort has been made to insure the accuracy of the information presented, and special effort has been made to assure that the information reflects the state-of-the-art, neither the American Wood Council nor its members assume any responsibility for any particular design prepared from this Span Calculator application. Those using this Span Calculator assume all liability from its use. ## Key features - Calculates joist and rafter spans - Supports all softwood and hardwood lumber - Uses 2021 NDS® for Wood Construction - Compares multiple species and grades - Handles common loading conditions ## Recent user reviews (10 of 27) All indexed reviews: https://appshunter.io/ios/app/span-calc/id380481343/reviews.md ### 5/5 — Works great! *2026-07-08, version 2.16.8* Seems to work just fine for us. Use it all the time, very smooth, doesn’t freeze up at all. Running on iPhone 17 Pro. ### 1/5 — Fails to run *2024-07-20, version 2.15.1* Fails to run on iOS 15.8.2 (iPhone 6s+) stopping on "Generating views…". ### 5/5 — Paul Catalano *2024-04-20, version 2.15.1* Span calculator has worked like charm for years but it recent crashed and needs to fixed 04-17-24 Ben worked diligently to repair the app and now it back to functional and we couldn’t be happier 04-20-24 ### 1/5 — Stopped working *2024-04-19, version 2.15.0* New update messed up app ### 1/5 — Unusable since last upgrade *2024-04-18, version 2.15.0* I have not been able to use the app this week. Something in the upgrade causes it to lock up. ### 1/5 — Latest update *2024-04-17, version 2.15.0* After the latest update now when I try to select anything it locks up. Worked just fine before. ### 1/5 — Paul Catalano *2024-04-17* Span calculator has worked like charm for years but it recent crashed and needs to fixed 04-17-24 ### 4/5 — Great App! *2024-04-16, version 2.15.0* Very useful for construction estimating job! However dropdowns do not work with the new update. I haven’t been able to use the app for the last couple days. ### 1/5 — Bad update *2024-04-14, version 2.15.0* Updated today and app stop working. Freeze when i try to choose species ### 3/5 — Calculator *2020-05-03, version 2.11.18* App froze when calculator came up on snow load at 120 lbs per sq. Ft. ## Frequently asked questions about Span Calc ### What lumber types does Span Calc support? Span Calc supports calculations for all species and grades of commercially available softwood and hardwood lumber as found in the 2021 National Design Specification® (NDS®) for Wood Construction. ### What loading conditions does Span Calc calculate for? Span Calc calculates spans for combinations of dead load plus live load (D + L), dead load plus snow load (D + S), or dead load plus roof live load (D + Lr). It does not address wind or seismic loads. ### Can Span Calc calculate spans for cantilevered or multiple-span joists? No, Span Calc does not address cantilevered joists and rafters, multiple-span joists and rafters, or spliced joists and rafters. It is designed for single-span members with adequate support at each end. ### What is the age rating for Span Calc? Span Calc has an age rating of 17+, indicating it is intended for mature users, likely due to the technical nature of its calculations and the construction industry context. ### How often is Span Calc updated? The latest version of Span Calc is 2.16.8, which was last updated on October 1, 2025. This suggests a relatively active development cycle for the application. ### What devices is Span Calc available on? Span Calc is available on iPhone, iPad, and iPod devices, making it accessible to a wide range of Apple users. ### What is the user sentiment for Span Calc based on its rating? Span Calc has a rating of 2.9 stars from 15 ratings. This indicates a mixed to slightly negative user sentiment, suggesting potential areas for improvement or user dissatisfaction. ### Does Span Calc require an internet connection to function? The provided data does not specify whether Span Calc requires an internet connection. However, as a calculation tool based on established standards, it is likely to function offline. ## Version history (last 5 releases) ### 2.16.8 — 2025-10-01 FIX : Application error when selecting short penny weight nails ### 2.16.3 — 2025-01-23 NEW: In session error handling and reporting ### 2.16.1 — 2024-11-21 FIXED: Intermittent UI issue when editing cell ### 2.16.0 — 2024-11-13 UPDATED : addressed a number of small UI bugs and quirks ### 2.15.1 — 2024-04-20 FIXED : Multi-select popups are not appearing ## Apps similar to Span Calc | App | Rating | Price | Category | | --- | --- | --- | --- | | [Feet and Inches Calculator](https://appshunter.io/ios/app/feet-and-inches-calculator/id1072241945) | 4.6 (401) | Free | Utilities | | [Measure Master Pro Calculator](https://appshunter.io/ios/app/measure-master-pro-calculator/id390273304) | 4.8 (4,204) | Free | Utilities | | [Material Estimator Calculator](https://appshunter.io/ios/app/material-estimator-calculator/id376071081) | 4.8 (2,927) | Free | Utilities | | [Construction Master 5 Calc](https://appshunter.io/ios/app/construction-master-5-calc/id370412148) | 4.8 (12,987) | Free | Utilities | | [Construction Master Pro Calc](https://appshunter.io/ios/app/construction-master-pro-calc/id370406446) | 4.8 (39,303) | Free | Utilities | | [RedX Walls - Design & Build](https://appshunter.io/ios/app/redx-walls-design-and-build/id1554953550) | 4.5 (365) | Free | Utilities | ## More apps by American Wood Council - [AWC Connection Calc](https://appshunter.io/ios/app/awc-connection-calc/id704968564) - [AWC UA Energy Calc](https://appshunter.io/ios/app/awc-ua-energy-calc/id1046147019) - [Heights and Areas Calculator](https://appshunter.io/ios/app/heights-and-areas-calculator/id1263104607) - [TR15 Acoustic Calculator](https://appshunter.io/ios/app/tr15-acoustic-calculator/id1507190662) - [CFS Checklist](https://appshunter.io/ios/app/cfs-checklist/id6483254114) All apps by American Wood Council: https://appshunter.io/developer/380481346 ## Related topics [rafter help](https://appshunter.io/ios/topics/rafter-help) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-13.*