Contractor Subcontractor Markup Calculator

How this calculator works

This calculator computes the recommended billable amount for a subcontractor scope by adding three components to the raw sub bid: management cost (the GC's supervisor and PM time), a risk premium (compensation for schedule, quality, and default risk), and a pro-rated bonding cost. The total GC cost is then divided by the gross margin complement to produce a recommended billable amount at the target margin.

GCs who pass sub costs through at cost — adding no markup — are performing management services for free, bearing risk for free, and leaving all the value from coordinating complex trades with the sub rather than sharing it with the company.

The three components of GC cost for a sub

Management cost: every sub requires GC oversight. Even a simple painting sub requires scope coordination, a submittal review for paint samples, at least two site inspections, and payment application processing. A complex mechanical/electrical/plumbing (MEP) package on a commercial project might require a full-time GC superintendent during the MEP rough-in phase — 150 hours of PM time is not unusual. This cost is real, burdened at the PM's loaded rate, and belongs in the billable amount.

Risk premium: the GC is contractually responsible to the owner for the sub's performance. If the electrical sub goes bankrupt in month 3 of a 6-month project, the GC absorbs the re-bid premium, the schedule delay penalty, and the lien exposure from the sub's unpaid material suppliers. The risk premium — typically 3-8% of sub cost for established subs, 8-15% for unfamiliar or high-risk subs — is the GC's compensation for accepting that risk.

Bonding cost: if the contract requires the GC to furnish a performance and payment bond, the bonding premium (typically 0.5-3% of contract value) must be allocated across the scope. The portion attributable to the sub's work is the sub's pro-rated share of the bonding premium, which is a direct cost of the engagement.

CFMA benchmarks for sub markup

The CFMA (Construction Financial Management Association) publishes benchmarks for typical sub markup in construction:

• Commercial GC work: 10-20% markup on sub costs for standard trade scopes
• Residential new construction: 15-25% on larger sub packages
• Design-build work: higher, because the GC bears design-coordination risk on top of performance risk

The "markup" figure in construction is typically expressed as a percentage of the raw sub cost (not the GC's loaded cost). This calculator shows both: markup on GC cost (which is the same as the target margin-based markup) and the implied markup on the raw sub cost, which is the number typically quoted in industry discussion.

Subcontractor compliance: COI and 1099

Before accepting a sub's bid and including them in a proposal, verify:

1. Certificate of insurance (COI): the sub must carry general liability (typically $1M/$2M minimum), workers' compensation (statutory limits), and commercial auto. The COI must name the GC as an additional insured on the GL policy. Accepting a bid without a current COI leaves the GC exposed to the sub's liability claims.

2. Form W-9: required before issuing any payment; needed to file Form 1099-NEC for payments over $600 to unincorporated businesses at year-end.

3. Lien waiver protocol: conditional lien waivers with each payment application, unconditional waivers with final payment. This is the primary protection against materialman's liens from the sub's suppliers.