Farm Machinery Rental vs Custom Work Calculator

Compare the working deadline before choosing rental or custom work

Comparing a daily machinery rental fee with a contractor quote can overlook the time needed to finish the job.
Work area, productive capacity and the time needed to collect, prepare and return equipment determine how many working days you need.
Rain or inaccessible fields may extend possession even when the machine is idle.
This calculator compares working days, calendar possession days, completion dates and cash costs for one identical farm operation.

It is designed for small farms, farmers operating rented equipment and family members helping arrange agricultural work in Korea.
Costs remain in KRW and the Korean program context was checked on 2026-09-15.
Enter a locally appropriate deadline and capacity: the tool does not determine harvest timing or equipment suitability.
Use the schedule to find an arrangement that fits, then confirm quotes and bookings with the rental center and contractor.

Understanding area, capacity and preparation time

From required working days to a completion date

Rounding up means even a partially used final day counts as one working day.
Expand the daily schedule to see which unavailable dates extend the plan.
Completion on the deadline itself counts as on time; subsequent dates are shown as calendar days late.
A separately confirmed rental limit is compared with all possession days, including both pickup and completion dates.

Unavailable dates should represent site dates when neither option can work.
Reflect the contractor’s existing bookings in its earliest start date and equipment availability in the rental pickup date.
Weekends and public holidays are not excluded automatically, and no weather forecast is fetched.
Unlisted dates are assumed available even after the deadline, so a late completion date is conditional on those later dates remaining workable.

Rental, transport, fuel and custom work charges

Cash line items are rounded to whole KRW before being added.
Own time value equals total hours multiplied by your chosen hourly value and is shown separately from cash spending.
Rental including own time adds that reference amount to rental cash cost.
Avoid double-counting family labor already entered as paid labor, and separately consider any substantial time needed to supervise a contractor.

How to use the calculator

1. Align the work scope: check whether both quotes cover only tillage or also levelling, residue handling or other tasks.
   Similar quote names can hide different quality or included operations.
   
2. Enter area and capacity: use the actual field area and hourly capacity with realistic daily hours.
   Add the full preparation, collection and return time once.
   
3. Set the working window: enter the available pickup date, actual deadline and unavailable dates.
   Use the contractor’s quoted start date and number of working days.
   
4. Enter cost details: separate rental fees, transport, fuel and other expenses from custom work rates, minimum fees and extras.
   Record the quote reference date and check that any discount remains valid during the job.
   
5. Review duration and cost together: check working days, possession days, the rental limit and both completion dates.
   If the cheaper option cannot fit, revise the start date or work allocation before choosing it.
   
6. Save the plan: download a TXT file containing inputs, daily schedules and cost details.
   Use it to confirm the actual booking and collection/return conditions with providers.
   

Fictional example: two work days, three possession days

Rental uses KRW 100,000 less cash, but rental including your time is KRW 20,000 more expensive than custom work.
If the provider confirms working-day-only billing, rental cash drops to KRW 220,000.
However, a rental limit of 2 calendar days is still exceeded by 3 possession days.
Fewer billed days do not resolve the duration constraint.
Every price and capacity in this example is fictional, not a local tariff or a machine specification.

Reading late completion and unfinished area

Maximum area by the deadline equals available working days × daily hours, minus preparation hours, multiplied by productive capacity.
If preparation consumes all available time, productive area is zero.
Unfinished area is the positive difference between the requested area and that capacity.
This measures working capacity separately from whether the equipment may be rented for that long.

Custom work must also fit its required working days after its earliest available start, so an apparently short job may still finish late.
If both options miss the deadline, the result calls for schedule changes.
An unknown rental limit stays unknown rather than being treated as satisfied.
Equipment skill and family availability also need separate consideration even when prices are close.

Useful planning scenarios

Limitations and checks before booking

• Confirm the local machine-specific fee, discount expiry, eligible users, maximum duration and extension conditions.
  No national discount rate or rental priority is applied automatically.
  
• Allow for collection and return times, cleaning and inspections.
  Hourly bookings, different daily capacities and repeated rentals cannot be represented precisely by one simple continuous schedule.
  
• Check contractor scope, minimum fees, extras and whether taxes are included.
  Subsidies and insurance reimbursements are not deducted automatically; confirm their actual payment and return conditions separately.
  
• The model supports up to 366 required work days, 366 unique unavailable dates and 10,000,000 m².
  These are product limits, not statutory rental periods or agricultural standards.
  
• Confirm operator training, safety equipment, insurance and site access with the provider and on site.
  Yield losses from delay, liability damages and accident risks are not assigned automatic monetary values.
  

Frequently asked questions