Comparison

Span Calc vs Stair Calculator

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Span Calc

Calculate maximum horizontal spans for wood joists and rafters using various lumber species and grades. Compares multiple options for common loading conditions based on NDS® standards.

Highlights
  • 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
Features
Read full description

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.

About

Stair Calculator

This app calculates essential parameters for stair construction, offering flexibility in input and providing multiple step set options. It supports various units and allows results to be easily copied.

Highlights
  • Calculate stair construction parameters
  • Flexible input for Run or Total Run
  • Determine largest and smallest step sets
  • Support for various units
  • Copy results to clipboard
Features
Read full description

Stair Calculator helps you calculate and compare staircase dimensions. FEATURES • Calculate using Run, Total Run, or Stair Angle • Enter a specific number of Runs or explore all calculated options • Support Metric and Imperial units • View detailed measurements and stair diagrams • Export results as a PDF or image • Copy results to the clipboard IMPORTANT Results are generated based on user-provided values and general calculation models. The app is intended for reference and educational purposes only. Please verify all measurements, local building requirements, and safety standards before actual construction. SUBSCRIPTION This subscription package offers unlimited access to all app features throughout the subscription period. • Payment will be charged to your Apple Account at confirmation of purchase. • The subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. • Your Apple Account will be charged for renewal within 24 hours before the end of the current period, and the renewal cost will be identified. • Subscriptions may be managed and auto-renewal may be turned off in your Apple Account Settings after purchase. • Any unused portion of a free trial period, if offered, will be forfeited when you purchase a subscription, where applicable. PRIVACY POLICY https://13520178.github.io/StairCalc/policy.html TERMS OF USE https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ CONTACT If you have any questions or suggestions, please contact us. Email: phannhatd@gmail.com

Screenshots

Span Calc4 screens
Stair Calculator3 screens

Verdict

The call

The clearest difference is rating: Stair Calculator at 4.1 against Span Calc's 3.0. Stair Calculator also leads on ratings volume (740 vs 16). Span Calc's advantage is in-app purchases (none vs 2) and update cadence (every 10 days vs every 3 months). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Stair Calculator sells 2 in-app purchases, starting at $9.99 per year. Span Calc asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Stair Calculator holds the better App Store score, 4.1 against 3.0. That said, the two scores are not equally well evidenced: Stair Calculator has 740 ratings behind it against 16, so its average is the more settled of the two. Written reviews complicate that: 30% of Span Calc's written reviews are positive against 21% of Stair Calculator's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Span Calc ships an update every 10 days, Stair Calculator every 3 months. The most recent releases landed on October 23, 2026 and October 24, 2026 respectively.

Scorecard6 real differences · 4 level
Span Calc versus Stair Calculator: the parameters behind the verdict, then further details
ParameterSpan CalcStair Calculator
PriceFreeFree
Rating3.0 (16 ratings)4.1 (740 ratings) — better
Positive reviews29.6% of reviews — better21.4% of reviews
Number of ratings16740 — better
Update frequencyEvery 10 days — betterEvery 3 months
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS14.2 — better15.0
Further details — not scored
Size168 MB1 MB
Age rating17+4+
DeveloperAmerican Wood CouncilPhan Nhat Đang

Customer experience

Span Calc

All ratings15 ratings
Positive53.3%
Neutral0.0%
Negative46.7%
Written reviews27 reviews
Positive29.6%
Neutral11.1%
Negative59.3%

Stair Calculator

All ratings738 ratings
Positive77.2%
Neutral5.0%
Negative17.8%
Written reviews28 reviews
Positive21.4%
Neutral7.1%
Negative71.4%

Bugs and requests

Span Calc

Not enough reviews yet to summarise bugs or requests.

Stair Calculator

Reported bugs

2 issues
  • Subscription numbers don't add up
  • Doesn't provide promised features after purchase

Requested features

3 requests
  • Option to uninstall app
  • Ability to calculate run based on rise and landing space
  • Provide more detailed diagrams and visuals

In-app purchases

None

Span Calc

No in-app purchases

2 purchases

Stair Calculator

Subscriptions1
  • Annual Premium Package7 Days trial$9.991 Year
One-time1
  • Unlock all features$5.99

Questions

Is Span Calc free?
Span Calc is free to download, with no in-app purchases.
Is Stair Calculator free?
Stair Calculator is free to download, with in-app purchases available.
Which has better reviews, Span Calc or Stair Calculator?
Stair Calculator is rated higher. Span Calc averages 3.0 out of 5 from 16 ratings, while Stair Calculator averages 4.1 from 740 ratings.
Do Span Calc or Stair Calculator have ads?
Neither Span Calc nor Stair Calculator shows ads.
Which is updated more often, Span Calc or Stair Calculator?
Span Calc ships an update every 10 days, and Stair Calculator every 3 months. Most recently, Span Calc was updated on October 23, 2026 and Stair Calculator on October 24, 2026.

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