AppGild
All Ideas
BeginnerFinance· Est. 2-3 days

Sub Bid Profit Calculator

Check whether a subcontractor quote still leaves enough margin before you say yes

Why people pay for this

It prevents the most expensive mistake in contracting: saying "yes" to a job that loses money. One avoided bad job pays for this tool 10x over.

Target Audience

Fence installers, general contractors, roofing contractors, concrete contractors, deck builders

Suggested Price

$49/year

Est. Build Time

2-3 days

What This Is

A fast profit sanity-check for small contractors who use subcontract labor. Enter the customer price, sub quote, materials, travel, disposal, and overhead — and instantly see your net margin with a clear "Accept," "Borderline," or "Renegotiate" recommendation. Prevents the gut-feeling math that leads to money-losing jobs.

Small contractors often receive a sub quote, glance at the total, and guess whether the job still works. They forget about permit costs, disposal fees, material overages, travel, and callback risk. By the time they realize the margin is too thin, they're already committed. A 60-second check before saying "yes" prevents the most common cause of unprofitable jobs.

How to Make Yours Different

Trade-specific cost buckets. A fence contractor's hidden costs (post-hole drilling, disposal, concrete, hardware) are different from a roofer's (tear-off, dump fees, flashing)

A "callback risk buffer" that automatically pads the estimate. Experienced contractors know that 5-10% of jobs have callbacks — this tool accounts for it

Margin guardrails with clear language: "Accept" (above target), "Borderline" (below target but above break-even), "Renegotiate" (below break-even or danger zone)

Preset job types so the contractor can select "6ft wood privacy fence" and have typical material and labor assumptions pre-filled

The Starter Prompt

Copy this into your vibe coding tool. Customize the [bracketed sections] with your industry knowledge.

Build me a "Sub Bid Profit Calculator" as a single-page web app for small trade contractors. Here's what I need:

**Core Features:**
- Inputs: total customer contract price, subcontractor labor quote, estimated material cost, travel cost, disposal/dump fees, permit cost, and a contingency buffer percentage (default 10%)
- A "Target Margin" setting (default 20%) that drives the recommendation
- Calculated outputs: gross profit, net profit after all costs, net margin percentage, and effective hourly rate (if job duration is entered)
- Clear recommendation: "Accept" (green — above target margin), "Borderline" (yellow — positive but below target), "Renegotiate" (red — below break-even or dangerously thin)
- Preset job types with pre-filled typical costs (e.g., "6ft Wood Privacy - 100 linear ft" auto-fills material estimates)
- "What-If" mode: adjust the customer price or sub quote to see what number makes the job work
- Export a plain text summary for records

**Design:**
- Designed for phone use in the field when a sub calls with a number
- Large number inputs with big +/- buttons for quick adjustment
- The recommendation badge should be impossible to miss
- Practical, no-frills design — dark navy or charcoal with clear white text

**Technical:**
- Single HTML file with embedded CSS and JavaScript
- All settings and presets stored in localStorage
- No external dependencies
- Should take under 60 seconds from opening the app to getting a recommendation

**Trade-specific:**
- Default job presets for [YOUR TRADE] with realistic material and labor assumptions
- [Enter your typical cost categories beyond labor and materials: permits, disposal, equipment rental, etc.]
- [Set your target margin percentage and explain your reasoning, e.g., "20% net after all costs"]

Got the prompt? You're halfway there.

Build it, test it on a real scenario, then come back to list it.

Pricing Guidance

$49/year

Annual subscription. Material costs and labor rates fluctuate yearly, and you can add new job types and cost categories.

One avoided money-losing job ($500-2,000+) pays for years of access. Annual updates let you adjust cost defaults seasonally and add new trade-specific preset categories.

AppGild takes a flat 20% commission. Monthly or annual subscriptions give your buyers ongoing value and give you recurring revenue, a win for everyone.

Getting Started

1

List every cost category in your trade beyond labor: materials, permits, disposal, travel, equipment rental, callbacks

2

Determine your real target margin — not the markup, but what you need to net after every cost is covered

3

Create 3-5 preset job types with typical costs filled in from your real experience

4

Build the first version and test it against recent jobs where you know the actual outcome

5

Show it to a contractor friend and ask if the presets match their experience

6

List on AppGild targeting your specific trade

Ready to build this?

Copy the prompt, open your building tool, and start. When it's ready, list it on AppGild and start reaching buyers.