General contractor estimating is a different discipline from specialty trade estimating. A concrete contractor estimates one trade. An HVAC company prices their own labor and equipment. A GC does something else entirely: they assemble a final bid by collecting quotes from 8 to 15 subcontractors, reconciling wildly different formats and scopes, applying their own overhead and markup, and submitting a number to an owner — usually under a hard deadline.

The process sounds straightforward until you're in it. Subs submit late. Two subs quote different scopes on the same section. One quote includes materials; the other doesn't. The electrical number comes in at 11 PM the night bids are due. The GC has to level all of it, make judgment calls on incomplete data, add their own indirect costs, and sign off on a price that will be binding for months.

Most GC estimating failures aren't math errors — they're process failures. Missing a sub quote. Using an outdated unit cost. Forgetting a line item in the general conditions. Submitting without time to review the final number. The right software doesn't replace the estimator's judgment; it handles the process so the estimator can focus on the judgment calls.

This guide covers what GC estimating software actually needs to do, the five platforms most used by commercial and residential GCs in 2026, the bid-day process in detail, and how to match a platform to your operation size and project mix.

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What GC Estimating Software Actually Needs
A platform built for specialty trades will miss the mark for a GC. The core capabilities that matter for general contracting are distinct: Quantity takeoff tools — For self-performed work and for verifying sub scopes, the estimator needs to measure from PDF or CAD drawings. Area, linear footage, count, and volume measurements taken directly from digital plans save time and reduce errors versus scaling measurements by hand. Subcontractor bid invitation and management — A GC running a competitive bid sends ITBs (invitations to bid) to multiple subs per trade, tracks who has responded and who hasn't, follows up on non-responders, and collects quotes by the deadline. Software that handles this in a structured workflow — rather than through a chain of emails and a spreadsheet — materially reduces the chance of missing a quote or inviting the wrong sub. Bid leveling and scope comparison — When three plumbing subs quote the same project, the GC needs to compare scope inclusions and exclusions side by side, not just compare numbers. One sub's $180,000 and another's $210,000 may represent the same scope once you account for what each includes. Bid leveling tools that enforce scope confirmation reduce this guesswork. Unit cost database — For general conditions, sitework self-performance, and preliminary budgets, the GC needs a database of unit costs that can be adjusted for project type, location, and current material pricing. A database that's been maintained with real project data is far more reliable than a published cost index alone. Overhead and markup calculation — The difference between a sub quote total and a GC bid includes general conditions (superintendent, site trailer, temporary utilities, dumpsters, portable toilets, project management time), insurance, bond premium, overhead, and profit. Software that applies these as structured line items — not a single percentage tacked on at the end — makes the cost transparent and easier to defend to an owner. Proposal and bid template generation — The final output is a formatted proposal or bid form. For private work, this is a GC-branded proposal with scope inclusions, exclusions, alternates, and payment terms. For public work, it may be an owner-provided bid form that the software can auto-populate. Templates save time and enforce consistency across estimators. Bid history and job costing feedback — Won bids should feed actual cost data back into the estimating database over time. If your historical data shows that your electrical estimates run 8% under actual on K-12 projects, that's information worth having before the next K-12 bid.
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Top 5 GC Estimating Platforms in 2026

1. STACK — Best for Digital Takeoff and Multi-Trade Bidding Price: $2,999–$4,999/year | Best for: GCs who receive full plan sets and need fast multi-trade digital takeoff
STACK is a cloud-based takeoff and estimating platform that handles the full pre-bid workflow from plan upload through estimate generation. For a GC, the relevant capability is multi-trade takeoff: you upload the plan set once and run takeoff across all trades — earthwork, concrete, masonry, framing, roofing — from the same drawing set with shared scale calibration.
The assembly system lets you build trade-specific assemblies that roll up labor, material, and equipment costs from a single takeoff measurement. The subcontractor bid management module lets you organize and compare sub quotes against trade divisions. Strengths:
Multi-trade takeoff from a single plan upload is efficient for GCs covering multiple divisions
Assembly library reduces setup time for repeated project types
Cloud access means the estimating team works from the same data
Integrates with several project management platforms Weaknesses:
Price is on the high end for smaller GC operations
Setup time to build accurate assemblies is substantial — plan for 20–40 hours of configuration
Sub bid management is functional but not as deep as dedicated ITB platforms like BuildingConnected
No AI or photo analysis — all measurement is manual Verdict: Strong choice for a GC with a dedicated estimator and a steady volume of plan-based bidding. The upfront configuration investment pays off on the 10th or 20th similar project type, not the first.
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2. Procore Estimating — Best for GCs Already on the Procore Platform Price: Add-on module pricing, typically $500–$1,500/month depending on volume | Best for: Mid-to-large GCs using Procore for project management who want estimating in the same ecosystem
Procore Estimating (built on the foundation of the Estimating module following Procore's acquisition of Willpower) integrates directly with Procore's project management, subcontractor management, and financial tools. For a GC who already uses Procore to run projects, adding estimating to the same platform closes the loop between bid and construction — sub quotes become subcontracts, budget line items carry forward, and bid-to-actual variance is tracked automatically.
The sub bid management in Procore leverages the Procore subcontractor network, which has broad adoption. Sending ITBs, tracking responses, and leveling quotes are handled within the platform without switching to a separate tool. Strengths:
Seamless handoff from estimate to project — no re-keying budget data at contract award
Subcontractor network access for ITB distribution
Bid leveling built into the workflow
Strong audit trail for bid decisions Weaknesses:
Only makes sense if you're paying for the broader Procore platform — expensive as a standalone estimating solution
Procore's overall pricing is substantial for smaller GCs
Estimating module is newer and less mature than STACK or Sage
Configuration and training requirements are significant Verdict: The right choice if you're already on Procore and the estimating-to-project handoff is a current pain point. A poor fit if you're evaluating estimating software independently of a broader platform commitment.
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3. Sage Estimating — Best for Commercial GCs Needing a Deep Unit Cost Database Price: Contact for pricing — typically $3,000–$8,000/year depending on modules | Best for: Commercial GCs doing $5M+ in revenue who need RSMeans integration and detailed assemblies
Sage Estimating (formerly Sage Timberline) is a legacy estimating platform that has been in the commercial construction market for 30+ years. The core advantage is the depth of the unit cost database and the assembly system, which supports extremely granular estimates broken down by CSI division. RSMeans cost data integration provides localized unit costs that can be updated by quarter.
For commercial GCs bidding public work, institutional projects, or complex private work where owners require detailed cost breakdowns, Sage's structure and audit trail are industry-standard. Many owners and CMs are familiar with Sage-formatted estimates. Strengths:
RSMeans integration provides reliable, location-adjusted unit costs
CSI division structure matches commercial bid requirements
Extremely mature platform with a large support ecosystem
Strong integration with Sage 300 Construction accounting Weaknesses:
Windows desktop application — limited cloud or mobile access
The interface reflects its age — steep learning curve and dated UX
High cost, high implementation time, and high ongoing maintenance overhead
Not practical for residential GCs or smaller commercial operators
No ITB or subcontractor management built in Verdict: The right tool for commercial GCs over $5M in revenue who bid public work and need a defensible, detailed cost breakdown by CSI division. Overkill and inaccessible for smaller operations.
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4. BuildingConnected — Best for Subcontractor Bid Management and ITB Workflow Price: Free tier available; Pro at $499/month | Best for: GCs who want the best subcontractor bid management and ITB distribution in the market
BuildingConnected (now part of Autodesk Construction Cloud) is the dominant platform for managing the ITB and bid collection workflow. Its network includes over 1.6 million construction companies, which means when you send an ITB for electrical work, you can reach qualified subs in your market who are already on the platform.
The bid board gives a real-time view of which subs have viewed the ITB, which have declined, which have submitted, and which haven't responded. Follow-up reminders are automated. Bid leveling tools let you compare scope inclusions and exclusions across sub quotes for the same division. Strengths:
The largest sub network in the market — unmatched ITB reach
Bid board and tracking workflow are industry-leading
Bid leveling and scope comparison tools are well-designed
Free tier covers the core ITB workflow for smaller GCs Weaknesses:
Not a takeoff or estimating platform — doesn't replace STACK or Sage for the estimating side
Most GCs use BuildingConnected alongside a separate estimating tool, adding complexity
Autodesk integration is improving but not seamless unless you're on the full ACC stack
Pro features become necessary quickly as bid volume grows Verdict: The best tool available for the sub bid management side of GC estimating. Many GCs use it in combination with a separate takeoff and estimating platform. If sub quote management is your primary pain point, start here.
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5. Ontrakt — Best for Pre-Bid Budgets and Proposal Follow-Up for Residential and Light Commercial GCs Price: Free beta | Best for: Residential and light commercial GCs who need fast preliminary estimates and automated proposal follow-up
Ontrakt solves a different problem than the platforms above. The core challenge it addresses is the pre-bid go/no-go decision: a potential client sends photos of their project, describes the scope, and the GC needs to decide within hours whether the project is worth pursuing and roughly what it would cost. Doing a full takeoff and sub solicitation for every lead is impractical. Most GCs either pass on unclear leads or give off-the-cuff numbers that don't hold up.
Ontrakt's AI analyzes project photos, site images, and uploaded specs or documents to generate a budget-level preliminary estimate automatically. For a GC, this means you can evaluate a new lead in 10 minutes, give the client a realistic budget range backed by a structured estimate, and decide whether to commit to the full bidding process. How the AI estimating works for GCs:
You upload photos of the project site, any available drawings or specs, and a brief description of scope. Ontrakt's vision AI analyzes the images to identify project type, scale, visible conditions, and complexity indicators. It generates a structured budget estimate by trade division — sitework, concrete, framing, mechanical, electrical — with line items and a total range.
This preliminary estimate serves two purposes: it helps the GC decide quickly whether the budget aligns with the project, and it gives the client a grounded expectation before sub quotes are solicited.
Once a proposal is sent, Ontrakt's automated follow-up sequences trigger on day 2, day 5, and day 10 for proposals that haven't received a response — so the GC doesn't lose jobs simply because the follow-up didn't happen. What Ontrakt currently doesn't have:
Plan-based digital takeoff tools for commercial projects
Subcontractor ITB distribution and bid leveling
RSMeans or CSI division cost database integration
Bid bond or public procurement workflow support Best for: Residential GCs and light commercial operators doing remodeling, additions, and tenant improvement work where the pre-bid phase is the bottleneck — deciding which leads to pursue and getting a credible number in front of the client fast.
Ontrakt is currently in open beta with full access available at no cost.
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The GC Bid-Day Process
Understanding the bid-day workflow clarifies what software features matter most. A typical competitive bid for a mid-size commercial project follows this sequence: Weeks 2–3 before bid day: The estimator reviews the plan set and specs, identifies the sub trades needed, and sends ITBs. For a commercial project, this typically covers 12–18 trade divisions. Each division gets invitations to 3–5 prequalified subs. The ITB includes the plan set, specs, bid form, and deadline. Week 1 before bid day: The estimator tracks ITB responses, follows up with non-responders, and begins the self-perform portion of the estimate — general conditions, sitework, any work the GC performs with their own crews. Unit costs for general conditions are entered at this stage: superintendent at $X per week for Y weeks, project manager at Z% of their time, temporary utilities as a lump, site fencing, dumpsters, portable toilets, safety equipment. Day before bid day: Most sub quotes arrive in the 24–48 hours before the deadline. The estimator receives them by email, phone, or through the bid management platform, enters them into the leveling sheet, and starts comparing. This is where scope gaps surface: the masonry sub quoted unit masonry but not the lintels. The roofing sub included membrane but not sheet metal flashing. Each gap is either resolved by contacting the sub or covered by the GC with a contingency. Bid day: Sub quotes continue arriving through the morning and early afternoon. A final round of calls goes out to subs who haven't submitted. The estimator makes last-minute substitutions — using a lower number from a sub who submitted late if it's within scope. Final overhead and markup are applied. The bid form is completed and reviewed. The GC submits, typically by hand-delivering or uploading to a bid portal, by the hard deadline. Post-bid: If the GC is low bidder, the estimate becomes the baseline for subcontracts and the project budget. Tracking actuals against the bid estimate is the feedback loop that improves future estimates.
Software that handles the ITB, leveling, and markup calculation stages reduces errors at the highest-pressure points in this process.
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GC Estimating Software Comparison
| Feature | STACK | Procore Estimating | Sage Estimating | BuildingConnected | Ontrakt |
|---|---|---|---|---|---|
| Digital Plan Takeoff | Yes | Yes | Yes | No | No |
| Sub Bid Invitation (ITB) | Basic | Good | No | Excellent | No |
| Bid Leveling | Basic | Good | No | Excellent | No |
| Unit Cost Database | Yes | Yes | RSMeans | No | AI-generated |
| General Conditions Builder | Yes | Yes | Yes | No | Basic |
| AI / Photo Estimating | No | No | No | No | Yes |
| Preliminary Budget (Pre-Bid) | Manual | Manual | Manual | No | Yes (AI) |
| Proposal Follow-Up | No | No | No | No | Yes (automated) |
| Project Management Integration | Moderate | Excellent (Procore) | Sage 300 | Autodesk ACC | No |
| Best Fit | Mid GC | Mid-large GC | Commercial GC | All GC sizes | Residential/light commercial |
| Price Range | ~$3–5K/yr | $500–1,500/mo | $3–8K/yr | Free–$499/mo | Free (beta) |
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Recommendations by Operation Type Commercial GC doing $5M+ in public and institutional work: Sage Estimating for the detailed cost database and CSI structure; BuildingConnected for ITB distribution and bid leveling. These two tools handle the full commercial estimating workflow at the cost and complexity level that large commercial work requires. Mid-size GC doing $1M–$5M in commercial and larger residential projects: STACK for plan-based takeoff and multi-trade estimating, combined with BuildingConnected for sub management. Procore Estimating is worth evaluating if you're already on the Procore platform or considering it. Residential GC or light commercial remodeler: Ontrakt for fast preliminary estimates, proposal generation, and automated follow-up. The AI photo analysis fits the pre-bid workflow for residential work where the lead stage determines whether a project is worth pursuing at all. GC whose primary bottleneck is sub quote management, not the estimate itself: BuildingConnected's free tier is the first thing to implement. The ITB and bid board workflow alone recovers significant time and reduces the risk of missing quotes on bid day.
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Try Ontrakt on Your Next Pre-Bid
If you're a residential or light commercial GC, the highest-value problem Ontrakt solves is simple: getting a credible preliminary number in front of a client quickly, without committing to the full bidding process for every lead.
Ontrakt is in open beta. Full access — AI photo estimating, proposal generation, automated follow-up, and invoicing — is free during the beta period. Start your free beta at ontrakt.com/beta →

Best General Contractor Estimating Software in 2026 — Bids, Takeoffs & Subcontractor Management

Top 5 GC Estimating Platforms in 2026

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