Adjust subdivision areas when RSR registered and FMB plotted values differ — per BSO 34-A rules. Pair with the FMB sketch calculator for bend distances. Upload an Excel file with headers or type data manually in the table.
Data formatExpected data format
Each row needs a survey subdivision and plotted area (FMB). Registered area (RSR) is entered only on parent subdivisions — not on part/child rows. Use the same layout in Excel (with headers) or in the manual table below.
| Survey subdivision | Registered area (RSR) | Plotted area (FMB) |
|---|---|---|
| Parent 100-1 | 2.00 | 2.02 |
| Part 100-1A | — via 100-1 | 1.02 |
| Part 100-1B | — via 100-1 | 1.00 |
| Parent 100-2 | 1.50 | 1.48 |
| Parent 100-A | 3.00 | 3.05 |
| Part 100-A1 | — via 100-A | 1.50 |
| Part 100-A2 | — via 100-A | 1.55 |
| Parent 100-B | 0.75 | 0.76 |
100-1, 100-2, 100-A, 100-B
100-1A, 100-1B, 100-A1, 100-A2. RSR comes from the parent row.
100).
When you enter a part subdivision (e.g. 100-1A), the tool asks for the registered area of its parent (100-1) and saves it for calculation. Part rows are adjusted proportionally using the parent’s RSR and the group FMB totals (BSO 34-A).
Survey data
Use either method below — you do not need to do both.
Upload Excel with headers
Choose a .xlsx or .xls file whose first row contains column headers (e.g. Subdivision, RSR Area, FMB Area). After upload, map each header to the required field.
Enter data manually
Type each row in the table below — survey subdivision, registered area (RSR), and plotted area (FMB). Use Add row for more entries.
| Survey subdivision | Registered area (RSR) | Plotted area (FMB) | Actions |
|---|---|---|---|
| Survey subdivision | Registered area (RSR) | Plotted area (FMB) |
Calculate
Adjusted areas
How It Works
1. Add your data
Excel: upload a file with a header row, then map columns. Manual: type subdivisions and areas in the table.
2. Apply BSO 34-A
The tool groups by survey number and applies variation rules to compute adjusted areas for each subdivision.
3. Export results
Review the adjusted area table with totals, then export to Excel for your records.
Corrections & questions
These guides are maintained for practising AP surveyors. If a step is outdated or wrong, tell us — we prioritise field corrections.
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