Calculator Inputs
Use aircraft-specific values from the current approved weight and balance record.
Example Data Table
| Scenario |
Empty weight |
Front seats |
Rear seats |
Baggage |
Fuel gal |
Takeoff weight |
Takeoff CG |
| Local training |
1665 lb |
340 lb |
0 lb |
20 lb |
35 |
2236 lb |
40.55 in |
| Cross country |
1665 lb |
340 lb |
220 lb |
55 lb |
40 |
2311 lb |
42.63 in |
| Heavy baggage review |
1665 lb |
360 lb |
300 lb |
120 lb |
38 |
2464 lb |
44.23 in |
Station moment: Weight × Arm.
Total weight: Sum of all station weights.
Total moment: Sum of all station moments.
Center of gravity: Total moment ÷ Total weight.
Takeoff weight: Ramp weight − Taxi fuel weight.
Landing weight: Takeoff weight − Planned trip fuel weight.
Forward CG limit: The tool interpolates between the selected low-weight and high-weight forward limit points.
How to Use This Calculator
Enter the aircraft empty weight and empty arm first. Add pilot, passenger, baggage, fuel, taxi fuel, and trip fuel values. Keep arms in inches. Keep weights in pounds. Review the ramp, takeoff, and landing rows. A result passes only when weight and center of gravity are inside the selected limits.
Change the limit fields when your approved data differs. Download the CSV for spreadsheet records. Use the PDF button for a simple report. Always compare the output with the current Pilot Operating Handbook and official aircraft records.
About This Cessna 172S Balance Tool
A Cessna 172S carries people, baggage, and fuel in fixed stations. Each station has an arm. The arm is the distance from the datum. Weight times arm creates moment. The total moment divided by total weight gives center of gravity. This calculator helps you organize those values before a flight.
Why Balance Matters
Good balance supports stable control. A forward center of gravity can require more elevator force. It can lengthen takeoff distance. It can reduce climb. An aft center of gravity can make the airplane less stable. It may also make stall recovery harder. The useful answer is not only total weight. The center of gravity must also stay inside the approved envelope.
Advanced Input Control
The form uses editable station arms. You can enter aircraft empty weight, empty arm, front seats, rear seats, baggage areas, fuel density, fuel burn, and limit values. This is useful because each aircraft has its own equipment list. It may also have a different empty weight from the sample defaults. Always copy the official values from the current weight and balance sheet.
Ramp, Takeoff, and Landing Checks
The calculator estimates ramp weight first. It then subtracts taxi fuel for takeoff weight. Planned fuel burn is subtracted again for landing weight. Each stage gets its own moment and center of gravity. The tool compares those values with the selected maximum weights and simplified envelope limits. It also checks baggage limits.
Interpreting the Output
Read the status lines together. A weight may pass while center of gravity fails. Baggage may also fail even when total weight passes. The table shows each station contribution. The summary shows ramp, takeoff, and landing conditions. Use both views before saving the report.
Safe Use
Use the result as a planning aid. Do not use sample values as aircraft authority. Confirm every number with the Pilot Operating Handbook, current equipment list, and approved loading data. If the aircraft was modified, use the latest reweighing record. Review fuel units carefully. Avgas is commonly estimated near six pounds per gallon, but your operating method may use another value. A correct balance check improves planning, reduces surprises, and supports safer decisions before engine start on each flight.
FAQs
Is this calculator approved for flight release?
No. It is a planning aid. Use the official Pilot Operating Handbook, current weight and balance sheet, and aircraft records before flight.
Can I change the station arms?
Yes. All station arms are editable. This lets you match the numbers from the exact Cessna 172S being loaded.
What fuel weight should I use?
The default is 6 lb per gallon. You can edit it. Use the method required by your school, operator, or aircraft documents.
Why are ramp, takeoff, and landing different?
Ramp includes all fuel before taxi. Takeoff subtracts taxi fuel. Landing subtracts planned trip fuel from the takeoff condition.
What happens when CG is outside limits?
The status shows outside selected limits. Move weight, reduce load, change fuel planning, or stop and review official loading data.
Can this page calculate baggage limits?
Yes. It checks area 1, area 2, and combined baggage limits. Edit the limits if your approved data differs.
Can I use it for another airplane?
You can edit the fields, but the labels target a Cessna 172S. A different aircraft needs its own arms, weights, and envelope.
Why show moment divided by 1000?
Many aircraft loading tables use moment divided by 1000. It keeps table values shorter while preserving the same balance calculation.