Financial management of a dental practice: chair margin

Quick answer. Managing a dental practice means tracking three management indicators: production per chair, chair occupancy rate and the practitioner's hourly cost. None is a regulatory threshold; they are management conventions. The time base starts from the legal working week of 35 hours (article L3121-27 of the Labour Code).

A dental practice often posts a comfortable turnover, yet the real result depends on details invisible on the bank statement: a chair left idle half a day each week, an assistant whose time is not linked to any production, a share of orthodontics that tips the practice into VAT. The annual accounts give the final score; they do not show where profitability leaks during the year.

This article focuses on the indicators specific to dentistry and on how to build them, without copying market benchmarks that do not exist. For detailed legal-structure and VAT questions, see our accounting support for dental surgeons.

Two practices with the same turnover can show very different profitability. One runs three chairs at full capacity; the other leaves two chairs half empty. Aggregate turnover hides this difference; per-chair and per-hour indicators reveal it.

Management means going one level below the total: per chair, per practitioner, per type of procedure. This is the logic we apply to any SME in our general principles of financial management, here adapted to the constraints of a dental practice.

Our reading. The right reflex is not to ask how much the practice billed, but how much each chair produced per open hour. A chair is a costly asset: equipment, floor space, assistance. Until it is tied to an hourly production figure, you are flying blind.

Production per chair#

Production per chair relates the fees generated by a given chair over a period. It is measured by day, month or year, and lets you compare chairs and spot the one that underperforms.

This is a management indicator with no official value. A chair dedicated to implant surgery does not produce like a chair used for conservative care: you compare a chair to itself over time, not to a market benchmark.

Chair occupancy rate#

The occupancy rate relates the hours actually worked on a chair to the hours it is open. A chair open forty hours but occupied twenty-eight shows 70 percent occupancy; the remaining twelve hours are uncovered fixed cost.

This is the fastest lever to pull: improving the schedule costs almost nothing and directly raises production. The same volume-margin logic is detailed in our article on distinguishing gross margin and net contribution.

The practitioner's hourly cost#

The full hourly cost relates all charges (rent, equipment, assistance, supplies, social contributions) to the number of genuinely productive hours. It acts as a floor: below it, a procedure loses money.

The denominator is not the gross legal duration. You start from the 35 weekly hours (article L3121-27 of the Labour Code) or the annual cap of 218 days for a manager on a day-count agreement (article L3121-58), then subtract leave, public holidays, training and non-productive administrative tasks. The result, often in the order of 1,100 to 1,400 billable hours a year, is a management assumption to parameterise, never an official figure.

Dental care and the supply of prostheses by dental surgeons are VAT-exempt (article 261, 4-1 of the General Tax Code; BOI-TVA-CHAMP-30-10-20-10). Two direct consequences for management.

First consequence: the VAT paid on a chair, a cone beam or a CAD/CAM unit is not recoverable. The investment cost per chair is therefore assessed inclusive of tax, and it is this gross amount that must be depreciated and built into the hourly cost. Reasoning net of tax, out of habit, understates the real cost of the equipment.

Second consequence: orthodontic appliances and aligners, which do not meet the definition of a prosthesis, are subject to VAT at the standard rate of 20 percent (BOI-TVA-CHAMP-30-10-20-10, paragraph 305, clarification of 8 February 2023). A practice developing a significant share of orthodontics may become partly liable for VAT, which changes the margin of the chairs concerned.

The underestimated risk. We regularly see hourly costs built on net-of-tax investments, as for a standard taxable activity. On equipment worth several hundred thousand euros, the gap between net and gross distorts the profitability floor and can lead to under-pricing. It is a silent error, never flagged by accounting software.

In practice. Here is the sequence we follow to set up monthly monitoring in the practices we support.

1. Map the chairs and the opening slots of each, in hours per week.
2. Link each billed procedure to the chair and the practitioner who performed it, via the practice software.
3. Calculate production per chair and per practitioner, month by month.
4. Measure the real occupancy rate by comparing hours worked and hours open.
5. Establish the full hourly cost from the practice's charges and the parameterised productive hours.
6. Track the chair margin and compare each chair to itself over time.

This build relies on a cost-of-production calculation method adapted to the practice, and on a dashboard in Pennylane or a decision-support tool. The choice of reporting tool is the subject of our comparison to compare Finthesis and Power BI.

Typical case: a three-chair practice#

Recently, a dental surgeon running three chairs approached us because his result was stagnating despite a busy schedule. Per-chair tracking showed that the third chair was only 55 percent occupied, largely on low-value care, while its fixed charges ran continuously. Without any extra spending, the practice redistributed the schedule towards higher-production procedures and reallocated half a day of assistance. The figures quoted are specific to this case and carry no benchmark value.

A mostly contracted practice collects quickly (third-party payment, immediate patient payment), but orthodontics, implantology and free-fee procedures are often spread over several instalments. Tracking patient payment schedules then becomes a cash-flow matter in its own right.

For the professional side (prosthesis laboratories, suppliers), payment terms between professionals are regulated: a default term of 30 days where nothing is stipulated, a cap of 60 days from the invoice or 45 days end of month (articles L441-10 to L441-16 of the Commercial Code). A flat indemnity of 40 euros per late invoice and penalties apply automatically; in the first half of 2026, the usual penalty rate stands at 12.15 percent (to be checked beyond 30 June 2026, as the rate is revised each half-year).

What the tax authority looks at. The boundary between VAT-exempt activity (care, prostheses) and taxable activity (orthodontics, aligners) must be clear in the accounts. A significant taxable share requires separate tracking of turnover and, where applicable, VAT returns. Consistency between billed procedures, collections and VAT regime is a classic control point.

• Build the gross (VAT-inclusive) cost of the equipment into the hourly cost, never the net amount.
• Check whether the share of orthodontics or aligners tips the practice into VAT at 20 percent.
• Do not compare a chair's production to a market benchmark: no official figure exists, compare a chair to itself.
• Distinguish the accounting result from real cash flow, especially when patient instalments are spread out.
• Anticipate electronic invoicing: receiving e-invoices is mandatory for all taxable businesses from 1 September 2026.

Setting up and monitoring these indicators is part of our outsourced finance director mission, combined with the keeping and review of your accounts. You can also rely on the 5 management KPIs to track for a cross-cutting view.