Model your marine repair shop's monthly revenue with labor and parts margins shown separately — so you know exactly what drives your net and where the biggest pricing opportunities are.
July, every slip in the harbor wants service yesterday and you're billing $750 a job between labor and parts. January, the lake freezes, the phone goes dead, and the same technician's wage is still landing in your account every two weeks like nothing changed. Marine repair isn't one business — it's a summer goldmine welded to a winter cash-flow problem, with parts values high enough that the markup line alone can outearn an entire auto shop. This calculator handles that reality: separate inputs for average labor per job and average parts per job, a parts markup percentage you control, and fixed costs for rent, employee wages, and overhead.
Parts markup is the leverage point most boat repair operators handle inconsistently. The marine parts supply chain is less standardized than automotive, which creates both the challenge of variable pricing from dealers and the opportunity to mark up harder-to-source components more aggressively. At a 40% markup on $400 in parts per job, you're generating $160 in parts margin per repair on top of labor revenue. Across 35 jobs per month, that's $5,600 in parts gross margin before the first dollar of labor billing.
Why marine parts markup requires active management
Auto parts have published OEM list prices that set customer expectations. Marine parts are murkier — a customer looking up an outboard impeller kit online might find prices ranging from $28 to $75 depending on brand and source. That variability gives the shop pricing flexibility, but it also requires active management to ensure your markup is both competitive and profitable. The standard in marine service is 40-50% markup on most hardware parts, with higher markup justified on emergency parts sourced quickly or items requiring dealer relationship overhead.
The tools tracks Parts Margin as its own KPI precisely because it moves independently of labor revenue. A month where labor volume drops by 20% hurts the top line, but if parts cost per job is similar, the parts margin contribution holds more stable. Conversely, a month where you handle complex engine rebuilds with $1,200+ in parts per job generates significantly more parts margin at the same markup rate. Know what percentage of your monthly net comes from parts versus labor — if either drops unexpectedly, you know where to look.
Seasonal volume in marine repair and how to model around it
Boat repair is among the most seasonal trades. Spring commissioning, pre-season engine service, and fall haulout create predictable volume spikes in most markets. Summer is peak revenue in recreational boating areas; winter is nearly dead in cold climates unless the shop pivots to storage and refit work. The calculator's Jobs Per Week input should be run at three levels: your peak season average, your shoulder season average, and your winter floor, with a monthly overhead that doesn't change across all three.
The gap between peak and trough is where most marine shops encounter cash flow stress. If January produces 3 jobs per week and July produces 15, the winter payroll on a full-time staff creates monthly losses that need to be funded from the summer surplus. Some shops address this by scaling down to one employee in winter; others carry the full staff and accept the seasonal loss as a cost of retaining skilled technicians. Run the calculator at winter job count and confirm the monthly loss is within the shop's ability to carry it.
Labor rate and the skilled technician premium
Marine diesel technicians, fiberglass specialists, and certified outboard technicians are scarce. The skilled shortage means labor rates in this trade have held up better than in some other marine-adjacent industries. Average labor billing in marine repair ranges from $95/hour for basic service to $140-$180/hour for specialist engine and electrical work. If your shop's average labor per job is $350, that implies roughly 2.5-3 hours at $120-$140 per hour — a realistic range for typical seasonal service work.
The $350 default is conservative. Marine shops handling complex repairs — engine rebuilds, fiberglass restoration, complete rewires — often see average labor per job well above $500, with corresponding parts values. If your shop's work skews toward high-complexity jobs, adjust both inputs upward and model the per-job profit. You may find that doing 8 high-complexity jobs per week is more profitable than 14 routine service calls, even if gross job count is lower.
Employee wages and the true cost of skilled marine labor
The default $4,000/month in employee wages reflects one experienced technician at roughly $22-$23/hour. Marine technician wages in high-demand markets can run $28-$35/hour for certified specialists, pushing the monthly wage for a single full-time tech to $4,800-$5,800. If your shop employs two technicians, wages alone may be $7,000-$9,000/month before overhead — which means breakeven job volume needs to be much higher than a solo-operator shop.
The ratio of wages to job volume is worth monitoring monthly. At $4,000 in wages and 8 jobs per week (34 jobs per month at 4.3 weeks), each job needs to carry roughly $118 in labor and parts contribution just to cover the technician's wage — before rent or other overhead. The calculator surfaces per-job profit so you can see instantly whether each job category is pulling enough margin to justify the skilled labor investment.
Positioning the shop for maximum margin per job
Marine shops that position on expertise rather than price typically hold margins that commodity repair businesses cannot. A shop certified by a major outboard manufacturer, with documented warranty repair capability, can charge $10-$20/hour more than an uncertified competitor and attract customers who need that specific credential. The calculator lets you model the impact: raise the average labor per job by $30 to represent a rate premium and see what it adds to monthly net.
Similarly, specialization in a profitable niche — classic wooden boat restoration, high-performance offshore service, or yacht management contracts — changes the parts and labor mix in ways that typically improve per-job margin. A yacht management retainer that generates $1,500/month in predictable service revenue is worth modeling as a retainer input alongside job-based revenue; the combination produces a much smoother monthly income curve than pure transactional work. If you've ever quoted from a hunch, run it through here once first.
How to use it
- Enter Jobs Per Week — use your realistic average across the year or for the specific season you're modeling.
- Set Avg Labor Per Job and Avg Parts Per Job from your actual invoice averages across a representative month.
- Adjust Parts Markup (%) to your typical markup on parts sold to customers.
- Fill in Monthly Rent, Employee Wages, and Monthly Overhead from your actual operating cost records.
- Read Gross Revenue, Parts Margin, Net Profit, and Per Job Profit — then model seasonal trough job count to check winter viability.
Who it's for
- Shop owner evaluating whether to hire a second technician for the season — Adds $3,600 in additional wages and models 6 more jobs per week in peak season — confirms the additional volume justifies the hire with $2,100/month net increase during the 5-month season.
- Marine mechanic opening a solo shop from a dealer background — Sets rent to $2,500, zero wages (solo), and models 6 jobs per week at the dealer's labor rate — finds breakeven is 4 jobs per week, confirming solo viability even before building a full client book.
- Shop reviewing parts pricing after a distributor contract change — Lowers parts cost per job from $400 to $340 after a better distributor arrangement and raises markup from 40% to 45% — calculates the combined $840/month improvement in parts margin.
- Owner modeling winter staffing decision — Reduces jobs per week to 3 in the winter model, finds the monthly loss at full staff is $2,200, and evaluates whether one technician reduced to part-time narrows that gap enough to avoid a layoff.
Key terms
- Per-job profit
- Monthly net profit divided by total jobs completed. The average contribution to business profit from completing one marine repair job, accounting for all fixed and variable costs.
- Parts markup
- The percentage added to the shop's acquisition cost for parts when billing the customer. The marine supply chain's variability creates wider acceptable markup ranges than in automotive.
- Commissioning
- The seasonal process of preparing a boat for active use after winter storage — typically involving engine service, systems checks, antifouling, and fitting out. Peak revenue period for most marine repair shops in northern markets.
Frequently asked questions
How should I handle warranty work in the model?
Warranty work reimburses at manufacturer rates, which are almost always lower than retail labor rates. If warranty work is more than 15-20% of your volume, use a blended average labor per job that reflects both warranty and retail rates in proportion. Alternatively, treat warranty and retail as separate models and compare the margins side by side.
What parts markup is standard in marine repair?
40-55% is typical for most hardware and mechanical components. Electrical parts, proprietary components, and emergency-sourced items often carry 50-70% markup. Canvas and upholstery materials are frequently marked up higher because the sourcing complexity and lead time justify a premium.
How do I account for storage revenue in this model?
Add storage income to your jobs-per-week model by treating each storage contract as a flat monthly contribution to overhead recovery. Alternatively, add storage revenue as a blended increase to your effective monthly revenue alongside repair jobs. Storage is typically high-margin, low-labor, and worth modeling separately if it's a significant part of the business.
What overhead should I include in the monthly overhead input?
Overhead beyond rent and wages covers liability and marine insurance, tool and equipment maintenance, shop supplies (not billed to jobs), merchant processing fees, yard fees if applicable, and any dealer certification or training costs. In a marine shop, boatyard rent may be a separate cost from shop rent if you're operating in a marina environment — include both.