Comparison
calcnote vs ClearCalcs: free ACI 318-19 concrete calculator compared
ClearCalcs (now Calcs.com) is a multi-material web platform covering steel, timber, and concrete calculations. calcnote is a free, focused concrete calculator covering columns, beams, footings, and load combinations to ACI 318-19.
This is an honest comparison: ClearCalcs is broader (steel, timber, slabs, walls in one subscription), while calcnote is deeper on concrete column and beam accuracy at zero cost. Each tool wins on different dimensions.
Quick comparison
| Dimension | calcnote | ClearCalcs (Calcs.com) |
|---|---|---|
| Price | Free, no login | $79-149/mo ($790-1,490/yr) |
| Platform | Web (any device, no login) | Web (login required) |
| ACI edition | 318-19 | 318-19 |
| Other codes | None | AS 3600, Eurocode 2 |
| Materials | Concrete only | Steel, timber, concrete, connections |
| Column shapes | Rectangular, circular | Rectangular only (ACI) |
| Biaxial bending | Exact integration | Bresler reciprocal |
| Slenderness | Sway + non-sway | Non-sway only |
| Beam design | Rect + T-beam (single span) | Rect (unlimited spans) |
| Footing design | Isolated + wall | Spread + wall |
| Load combinations | Yes (ASCE 7-22) | No standalone module |
| Reports | PDF + editable .docx | Branded PDF |
| Verification | 51 TCs (columns, beams, footings); 0.03% vs spColumn | No published verification |
| AI explanation | Yes (unique) | "CalcsAI" (undocumented) |
Detailed feature comparison
Column accuracy and method
calcnote uses exact strain-compatibility integration per ACI 318-19 Section 22.2 for both uniaxial and biaxial bending. This is the same method used by spColumn and ENERCALC. calcnote is cross-validated against spColumn to within 0.03% on nominal capacity. See the verification index for the complete suite, the verification summary, and the Wight Example 11-1 witness page.
ClearCalcs uses the Bresler reciprocal approximation for biaxial bending, valid per ACI 318-19 Section 22.4.3 but less precise near the balanced point and in tension-controlled regions. ClearCalcs' documentation limits the biaxial check to a subset of axial load levels.
calcnote supports circular columns (tied and spiral) with automatic worst-rotation search. ClearCalcs' ACI column calculator supports rectangular sections only.
What calcnote adds
- Load combination module: ASCE 7-22 LRFD + ASD with seismic overstrength combinations
- T-beam design: flexure, shear, Bischoff Ie deflection, crack control per Cl 24.3.2
- Footing module: isolated + wall with bearing, punching shear, one-way shear, flexure, development length, interface/dowel checks
- 3D P-Mx-My surface: interaction surface with demand-plane visualization
- AI-generated explanation: narrative verified against the deterministic engine
- Editable .docx reports: for submittal packages (vs branded PDF)
- Published verification: 51 test cases, 26 methodology spokes, 49-term glossary
What ClearCalcs does that calcnote does not
- Multi-material platform: steel, timber, and concrete calculations in one subscription
- Multi-code support: AS 3600:2018 and Eurocode 2 in addition to ACI
- Multi-span beams: unlimited supports and loads
- Slab design: one-way concrete slab to ACI 318-19
- Linked calculations: column output feeds directly into footing input
- Project saving and history: calculations saved across sessions
- Professional support: included with subscription; enterprise and academic plans available
ClearCalcs' breadth means one subscription covers more of a firm's calculation needs. calcnote's depth means higher accuracy and more features within concrete column/beam/footing design.
Workflow comparison
calcnote: open your browser, enter inputs, get the result immediately. No account, no subscription, no trial expiration. Share results as PDF or editable .docx.
ClearCalcs: create an account, select the calculator for your code and material, configure inputs, link elements together. Powerful for firms needing multi-material coverage under one platform. Branded PDF output.
Pricing comparison
| Tool | Monthly | Annual |
|---|---|---|
| calcnote (columns + beams + footings + load combos) | $0 | $0/year, forever |
| ClearCalcs Basic | $79/mo | $790/year |
| ClearCalcs Pro (includes column calculator) | $119/mo | $1,190/year |
| ClearCalcs Ultimate | $149/mo | $1,490/year |
ClearCalcs' concrete column calculator requires the Pro plan or higher. Prices from Calcs.com's website; may change. ClearCalcs offers a 14-day free trial.
When to choose each tool
Choose calcnote when
- You need a quick ACI 318-19 column, beam, or footing check without subscribing
- You need exact biaxial integration (not Bresler approximation)
- You need circular column support with automatic rotation search
- You want an editable .docx report for your submittal package
- You want AI-generated explanations of results
- Budget is a constraint
Choose ClearCalcs when
- You need steel, timber, and concrete calculations in one platform
- You need AS 3600 or Eurocode 2 code support
- You need multi-span continuous beam design
- You need linked calculations between elements (column to footing)
- Your firm standardizes on ClearCalcs for multi-material workflows
- You need slab design
Frequently asked questions
Is calcnote as accurate as ClearCalcs for column design?
calcnote uses exact strain-compatibility integration per ACI 318-19 Section 22.2 for both uniaxial and biaxial bending. ClearCalcs uses the Bresler reciprocal approximation for biaxial, valid per ACI 318-19 Section 22.4.3 but less precise near the balanced point. For uniaxial bending, both tools solve the Whitney stress block. calcnote is verified against spColumn to within 0.03%.
Does ClearCalcs support circular columns?
ClearCalcs' ACI column calculator supports rectangular sections only. calcnote supports both rectangular and circular columns, including tied and spiral configurations, with automatic bar-ring rotation search for worst-case capacity.
Can ClearCalcs handle sway frames?
ClearCalcs supports non-sway moment magnification only. calcnote supports both sway and non-sway slenderness per ACI 318-19 Sections 6.6.4.5 and 6.6.4.6, on both axes for biaxial columns.
Is ClearCalcs the same as Calcs.com?
Yes. ClearCalcs rebranded to Calcs.com. The domain clearcalcs.com redirects to calcs.com. The product, pricing, and calculators are unchanged.
Is calcnote really free?
Yes. calcnote is completely free with no login required, no calculation limits, and no trial period. All features, including column, beam, footing, and load combination calculators, are available at no cost.