Calculation guide
How operating costs and Live Offer results work
KeenGig converts saved vehicle, maintenance, and business assumptions into consistent per-distance and per-hour estimates. These are planning estimates—not accounting, tax, mechanical, or legal advice.
1. Vehicle cost per distance unit
Depreciation per distance unit
(Purchase cost − expected resale value) ÷ (expected resale mileage − purchase mileage)
Example: a vehicle purchased for $20,000 at 50,000 miles and expected to sell for $5,000 at 150,000 miles has $15,000 of modeled depreciation across 100,000 miles, or $0.15 per mile.
Current mileage does not change the lifetime average depreciation rate. It records progress through the ownership period and can be used to understand remaining mileage. Historical purchase cost is an average-lifecycle model; a current-market-value model could produce a different forward-looking estimate.
General maintenance per distance unit
General maintenance spending ÷ distance covered by that spending
Use this for maintenance not already entered as a separate tire, oil, or brake reserve. Including the same work in both places will double-count it.
Fuel per distance unit
- MPG: fuel price ÷ miles per gallon
- km/L: fuel price ÷ kilometres per litre
- L/100 km: fuel price × litres per 100 km ÷ 100
Total variable vehicle cost = depreciation + general maintenance + fuel
2. Tires and scheduled service
Each scheduled item becomes a reserve per distance unit:
Expected service cost ÷ replacement interval
Only the tire set marked as currently mounted contributes a tire reserve to new miles and Live Offer calculations. Oil-change and brake reserves continue to apply to every driven distance unit.
KeenGig stores accumulated wear separately for all-season and winter tires. When current vehicle mileage increases, the difference from the last tracked odometer is credited to the tire set that was active before the save. When changing tires, update the current odometer and select the newly mounted set in the same save; the distance since the previous save is credited to the old set before the switch.
On first setup, enter the miles already driven on each set. The “installed at” fields remain maintenance records; accumulated miles used determine estimated remaining tire life.
3. Recurring vehicle and business costs
Annual insurance, inspection, registration, and light-bulb estimates are divided by 12. Monthly fluids, car washes, cleaning supplies, other vehicle costs, and replacement-vehicle savings are used directly.
Replacement-vehicle savings is additional to depreciation. Depreciation models the vehicle value consumed by driving; the replacement reserve is an optional cash-savings goal. Set the reserve to zero if you do not intend to count both.
Business phone cost is:
Monthly phone bill × business-use percentage ÷ 100
Supplies, subscriptions, and other business overhead are added at their monthly values.
Total monthly operating cost = monthly-distance vehicle cost + scheduled reserves + recurring vehicle costs + business overhead
Operating overhead per distance unit = monthly overhead and reserves ÷ expected monthly business distance
4. Sustainable hourly baseline
Monthly available hours = available hours per week × 52 ÷ 12
Operating cost per available hour = total monthly operating cost ÷ monthly available hours
Sustainable hourly baseline = operating cost per available hour + Minimum Acceptable Hourly Profit
Minimum Acceptable Hourly Profit is the minimum hourly profit you are willing to work for after operating costs. It is a minimum standard, not an aspirational wage goal.
The sustainable hourly baseline is the gross hourly revenue level intended to cover modeled operating costs while leaving that minimum acceptable profit. It is not a guaranteed wage or tax-adjusted take-home amount.
5. How the Live Offer Calculator evaluates an offer
Distance and time
Estimated actual distance = offered distance + expected unpaid return distance
Expected unpaid return distance = offered distance × unpaid-return percentage ÷ 100
Projected time = offered minutes + estimated additional minutes
Allocated offer costs
Fuel, depreciation, general maintenance, scheduled-service reserves, and monthly overhead are converted to per-distance rates and multiplied by estimated actual distance. Offer-specific costs are then added.
Full offer cost = fuel + depreciation + general maintenance + scheduled reserves + allocated recurring overhead + offer-specific costs
Displayed results
- Gross hourly = offer payout ÷ projected hours
- Gross per distance unit = offer payout ÷ estimated actual distance
- Profit after operating costs = offer payout − full offer cost
- Net hourly = profit after operating costs ÷ projected hours
- Net per distance unit = profit after operating costs ÷ estimated actual distance
Tax and savings reserves
Tax and savings reserves are calculated only on positive profit after operating costs. A loss does not create a negative reserve.
Tax reserve = max(0, profit after operating costs) × saved tax percentage ÷ 100
Take-home estimate = profit after operating costs − tax reserve − savings reserve
Tax is intentionally not included as an operating expense because it depends on taxable profit and individual circumstances.
Important assumptions
- Fixed monthly costs are allocated by distance. If actual monthly business distance differs from the saved estimate, per-offer allocation will differ.
- The model is linear: depreciation and scheduled service are averaged across distance.
- Current mileage and service mileage are records; they do not predict an exact failure or service date.
- Recorded ledger purchases do not automatically replace planning assumptions. This prevents a one-time purchase from distorting every future offer.
- Do not enter the same expense in both general maintenance and a detailed reserve unless intentional.