Custom Calculators
Custom Calculators let you create guided data-entry forms that are pre-wired to specific emission factors. Use them to standardise data collection across teams or suppliers who may not know exact GHG accounting rules.
What calculators do
A calculator:
- Presents a set of input fields (quantity, distance, headcount, etc.)
- Applies a formula that maps those inputs to one or more activity totals
- Looks up the appropriate emission factor(s)
- Creates the underlying emission entry/entries automatically
Creating a calculator
Navigate to Settings → Calculators → New Calculator.
Step 1 — Basic info
| Field | Description |
|---|---|
| Name | Shown to users and in entry records |
| Description | Explain what the calculator is for |
| Scope | Scope 1, 2, or 3 |
| Category | Activity category the calculator will log to |
| Icon | Optional visual identifier |
Step 2 — Input fields
Add one or more input fields. Each field has:
| Property | Options |
|---|---|
| Label | Display name |
| Field type | Number, Dropdown, Checkbox, Date |
| Unit | e.g., km, kWh, litres, nights |
| Required | Yes / No |
| Help text | Short tooltip explaining what to enter |
| Validation | Min / Max / Regex |
Step 3 — Emission factor mapping
Map each input field (or a formula combining fields) to an emission factor:
- Select factor source: auto-match, pin to specific factor, or use a variable factor per dropdown option
- Define the calculation formula using field references:
emission = {distance_km} * {passengers} * factor
Use {field_name} tokens. Standard operators (+, -, *, /) and grouping with () are supported.
Step 4 — Output preview
Enter sample values. The preview shows the computed tCO₂e and confirms which entries will be created.
Using a calculator
Calculators appear under Carbon Tracking → Calculators. Users who have the Data Entry role or above can run any calculator in their organisation.
- Click the calculator name
- Fill in the input fields
- Review the calculated emissions
- Click Submit to create the entries
Entries created by a calculator are tagged with the calculator name in the Data source field for traceability.
Calculator groups
Group related calculators together for easier navigation:
- Go to Settings → Calculator Groups → New Group
- Give the group a name and optional description
- Drag calculators into the group
Groups appear as expandable sections on the calculators list. You can assign a default calculator to open when the group is expanded.
Editing and versioning
When you edit a calculator that has already produced entries, AlchemOS Positive:
- Saves the old version (accessible under History)
- Tags existing entries with the calculator version that produced them
- Does not retroactively recalculate past entries
Permissions
| Role | Can create | Can edit | Can run | Can delete |
|---|---|---|---|---|
| Admin | ✅ | ✅ | ✅ | ✅ |
| Manager | ✅ | Own | ✅ | Own |
| Data Entry | ❌ | ❌ | ✅ | ❌ |
| Read Only | ❌ | ❌ | ❌ | ❌ |