Wet rate vs dry rate aircraft billing, explained. How each model works, which fits flight schools, flying clubs, and leaseback owners, and how to price it correctly.
A flight school setting an hourly rate has to pick between two billing models: wet (fuel included) or dry (aircraft only, fuel billed separately). The choice changes your revenue predictability, your students' costs, and how much fuel-receipt reconciliation lands on your front desk every month.
Both work. The right answer depends on how your operation buys fuel and how much variance in fleet usage you're willing to absorb on your margins.
Run the math for your own fleet on the wet vs dry rate calculator.
A wet rate folds fuel into the hourly charge. The school buys fuel in bulk, marks the per-hour rate to cover average fuel burn at the bulk price, and adds a margin. Students see one number on the invoice and never touch the fuel pump.
Concretely: a Cessna 172 burning 8 gph at cruise, with on-field fuel at $6.20/gal, has a fuel cost of about $49.60 per Hobbs hour. Set the rate at $160/hr wet and the school covers fuel, oil, maintenance reserve, insurance, and depreciation in a single line.
Wet rates work well when you have bulk fuel purchasing (a fuel truck, an on-field FBO arrangement), your fleet has similar fuel burns, and you want simple billing students can compare directly. Most schools running wet rates review pricing quarterly to keep up with fuel-price volatility. If you lock in a rate and 100LL spikes for three months, your margin gets squeezed until you adjust.
A dry rate charges only for aircraft time. Fuel is the renter's problem, either purchased directly at the pump or billed as a separate line item at actual cost.
For the same 172, a dry rate of $115/hr covers maintenance reserve, insurance, and depreciation. Fuel is added per flight at whatever it cost: 8 gph × $6.40/gal = $51.20/hr in fuel. Total: about $166/hr, varying with where the renter fueled.
Dry rates fit operators who don't have bulk fuel arrangements, fleets with very different fuel burns (a primary trainer versus a complex retract), and operators who want fuel cost to flow through transparently. The downside is variability. A student who fueled at a remote field at $7.50/gal has a different cost than the one who fueled at home for $5.80. Billing accurately means tracking actual fuel consumed, not estimated burn.
A common compromise: schools sell fuel from their own pump at a fixed price and require members to fuel only there. That effectively recreates a wet rate with a transparent fuel line item.
A lot of modern flight school management systems let you bill dry rate plus a separate fuel line. You get the best of both: a stable aircraft rate that's easy to compare to other schools, fuel cost visible to the student as its own line, and the ability to adjust fuel pricing per invoice without touching the aircraft rate.
A typical invoice:
Flight — N1234C | 1.4 Hobbs hrs × $115/hr = $161.00
Fuel — 11.2 gal | 11.2 × $6.20/gal = $69.44
CFI instruction | 1.4 hrs × $65/hr = $91.00
────────────────────────────────────────────────────────
Total = $321.44
Transparency builds trust. Students don't second-guess the bill when they can see exactly what they paid for.
Whether wet or dry, the hourly rate has to cover real costs. Here's the breakdown most schools should be running:
| Cost component | How to calculate |
|---|---|
| Fuel (wet only) | Avg burn × avg fuel price per gallon |
| Oil consumption | $3–5/hr for typical GA aircraft |
| Maintenance reserve | Historical annual MX cost ÷ annual hours flown |
| Annual inspection reserve | Annual inspection cost ÷ hours flown per year |
| Engine reserve | Engine overhaul cost ÷ TBO hours |
| Insurance | Annual premium ÷ hours flown per year |
| Hangar / tiedown | Monthly cost × 12 ÷ hours flown per year |
| Avionics & upgrade reserve | Estimated upgrade cost ÷ years |
| Depreciation | If preserving aircraft value matters to you |
Most small flight schools underestimate engine and maintenance reserves when setting rates. A 172 running 800 hours a year with a $30,000 overhaul at 2,000 hours owes $15/hr in engine reserve alone, before maintenance, insurance, or fuel.
For owners running the same math on their own aircraft, the cost-of-ownership calculator folds all of this into one number.
If you operate 172s for primary training and a Piper Arrow for complex training, they need separate rate cards. The Arrow burns more fuel, costs more to insure, and has different maintenance economics. Averaging across the fleet creates cross-subsidies — your most active 172 students end up paying for an aircraft they're not flying, and your Arrow renters get under-charged.
The fix is per-aircraft pricing. Modern flight school management software (Aloft360 included) lets you configure billing type, hourly rate, fuel price, and CFI rate per aircraft. Change the rate in one place; future invoices pick it up automatically.
The short version:
Compare wet and dry side-by-side at your utilization →
If you're standing up a new operation or restructuring billing, see also our take on flight school management software and the breakdown of flying club scheduling software.