Short answer: to level subcontractor bids, list every scope item for the trade, mark each bid as included, excluded or qualified for that item, give every item a "plug" value (what it would cost you to cover it yourself), then add the plugs for each bid's gaps to its base price. The lowest leveled number is the real low bid, and it is often not the lowest number on the bid form.
Below is a worked drywall example with three bids, the arithmetic, and the one assumption that can flip the result.
Why the lowest base bid is often not the cheapest
Subcontractors price slightly different jobs. One leaves out scaffolding, another "assumes by others" for cleanup, a third qualifies shaft wall "per manufacturer's standard detail". Each of those gaps becomes your cost after award, usually as a change order. Leveling turns every bid into the same scope so you compare like with like.
Step by step
- Write the scope checklist first, from the drawings and specs, before you read the bids. Otherwise the most complete bid quietly becomes your scope.
- Give every item a plug value: your own estimate of what it costs to buy that item separately at this point in the job (not the cheapest sub's line price).
- Read each bid's inclusions, exclusions and qualifications and mark each item I (included), E (excluded) or Q (qualified: included with a condition you can't fully price).
- Add the adjustments: excluded = full plug; qualified = a share of the plug. 50% is a common starting point; use 100% if the qualification is vague.
- Rank on the leveled total, then call the top two to clear the qualifications before you award.
Worked example: drywall package, three bids
Base bids as submitted: Sub A $412,000, Sub B $389,500, Sub C $398,000. B looks $8,500 cheaper than C and $22,500 cheaper than A.
| Scope item | Plug value | Sub A | Sub B | Sub C |
|---|---|---|---|---|
| Level 5 finish at lobby walls | $7,800 | I | E | I |
| Shaft wall at stairs and elevator | $18,500 | I | E | Q |
| Fire-rated corridor assemblies | $12,000 | I | I | I |
| Lift and scaffold access | $9,200 | I | E | E |
| Daily cleanup and debris haul | $4,600 | I | Q | E |
| Sound-attenuation batts | $11,300 | E | I | I |
Adjustments, with qualified items carried at 50% of the plug:
- Sub A: batts excluded, so +$11,300. Leveled: $423,300
- Sub B: Level 5 $7,800 + shaft wall $18,500 + access $9,200 + half of cleanup $2,300 = +$37,800. Leveled: $427,300
- Sub C: half of shaft wall $9,250 + access $9,200 + cleanup $4,600 = +$23,050. Leveled: $421,050
| Base bid | Adjustments | Leveled total | Rank | |
|---|---|---|---|---|
| Sub A | $412,000 | +$11,300 | $423,300 | 2 |
| Sub B | $389,500 | +$37,800 | $427,300 | 3 |
| Sub C | $398,000 | +$23,050 | $421,050 | 1 |
The "low bidder" B drops to last. Its price was low because it covered less.
The assumption that decides it: how you carry qualified items
C beats A by only $2,250, and that depends on the 50% share for C's qualified shaft wall:
| Qualified items carried at | Sub A | Sub B | Sub C | Low bid |
|---|---|---|---|---|
| 0% (treat as included) | $423,300 | $425,000 | $411,800 | C |
| 50% | $423,300 | $427,300 | $421,050 | C |
| 100% (treat as excluded) | $423,300 | $429,600 | $430,300 | A |
So don't award on the spreadsheet alone. When the result swings on a qualification, send a written clarification ("Confirm shaft wall is included per the specified UL assembly, no exclusions") and re-level with the answer. One phone call here is worth up to $9,250.
Common leveling mistakes
- Using the cheapest sub's line price as the plug. Buying one item separately after award usually costs more than it did inside a full package.
- Leaving "by others" in. Every "by others" needs a named other, or it's yours.
- Ignoring alternates and unit prices. Level the base bid first, then compare alternates on their own lines.
- Forgetting schedule and bonding. A sub who can't meet the schedule or provide a bond if you need one isn't the low bid at any price.
- Not keeping the record. Save the leveling sheet with the award; it explains your choice if the owner or an auditor asks.
A spreadsheet that already does this
If you'd rather not build the formulas, Sheet Reserve's subcontractor bid leveling sheet has a scope checklist with plug values, I/E/Q status per sub, an adjustable qualified-item share and a leveled ranking. You can preview it without an account. For public or unit-price bids, the bid tabulation sheet ranks bids and flags unbalanced lines.
Downloads (XLSX, ODS, CSV and more) come with the Sheet Reserve membership, $19.85 a year, which covers the whole library of about 160 templates and datasets.
Written with help from Yunus's AI assistant. The bid figures are an illustrative example, not a real project. Sheet Reserve is Yunus Emre Vurgun's project, and the membership link above is promotional.