Documentation Index
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Computed variables allow form owners to define calculated values using formulas. These variables can reference form fields, use functions, and even reference other computed variables. They work seamlessly with mentions throughout your form.
Overview
Computed variables are powerful calculated fields that:
- Evaluate live during form fill (client-side)
- Evaluate on submission for integrations and notifications (server-side)
- Support Excel-like formulas with math, text, and logic functions
- Chain together to create complex calculations
- Work with mentions anywhere you can use field references
Creating Computed Variables
Accessing the Variables Tab
- Open your form in the editor
- Click on Settings (gear icon)
- Navigate to the Variables tab
- Click Add Variable to create a new computed variable
Variable Configuration
Each computed variable has:
| Field | Description |
|---|
| Name | A descriptive name for the variable (e.g., “Total Price”) |
| Formula | The calculation formula using fields, functions, and operators |
- Field picker - Insert form fields as references
- Function picker - Browse and insert available functions
- Live validation - Real-time syntax checking
- Preview - See sample output as you type
Field References
Reference form fields using curly braces:
In the editor, you can click the field button to insert fields as interactive pills.
Operators
| Operator | Description | Example |
|---|
+ | Addition / Concatenation | {price} + {tax} |
- | Subtraction | {total} - {discount} |
* | Multiplication | {price} * {quantity} |
/ | Division | {total} / {count} |
= | Equals | {status} = "active" |
<> | Not equals | {status} <> "inactive" |
< > | Less/Greater than | {age} > 18 |
<= >= | Less/Greater or equal | {score} >= 90 |
Text Concatenation
Use + or CONCAT() to join text:
"Hello, " + {name} + "!"
CONCAT({first_name}, " ", {last_name})
Available Functions
Math Functions
| Function | Description | Example |
|---|
SUM(...) | Add multiple values | SUM({item1}, {item2}, {item3}) |
AVERAGE(...) | Calculate mean | AVERAGE({score1}, {score2}) |
MIN(...) | Find minimum | MIN({price1}, {price2}) |
MAX(...) | Find maximum | MAX({bid1}, {bid2}) |
ROUND(value, decimals) | Round number | ROUND({total}, 2) |
FLOOR(value) | Round down | FLOOR({price}) |
CEIL(value) | Round up | CEIL({quantity}) |
ABS(value) | Absolute value | ABS({difference}) |
MOD(value, divisor) | Remainder | MOD({number}, 2) |
POWER(base, exp) | Exponentiation | POWER({base}, 2) |
SQRT(value) | Square root | SQRT({area}) |
Text Functions
| Function | Description | Example |
|---|
CONCAT(...) | Join text | CONCAT({first}, " ", {last}) |
UPPER(text) | Uppercase | UPPER({name}) |
LOWER(text) | Lowercase | LOWER({email}) |
TRIM(text) | Remove whitespace | TRIM({input}) |
LEFT(text, n) | First n characters | LEFT({code}, 3) |
RIGHT(text, n) | Last n characters | RIGHT({phone}, 4) |
MID(text, start, len) | Substring | MID({ssn}, 4, 2) |
LEN(text) | Text length | LEN({message}) |
SUBSTITUTE(text, old, new) | Replace text | SUBSTITUTE({url}, "http", "https") |
REPT(text, n) | Repeat text | REPT("*", {rating}) |
Logic Functions
| Function | Description | Example |
|---|
IF(condition, true_val, false_val) | Conditional | IF({score} >= 90, "A", "B") |
AND(...) | All true | AND({age} >= 18, {consent}) |
OR(...) | Any true | OR({premium}, {trial}) |
NOT(value) | Negate | NOT({disabled}) |
ISBLANK(value) | Check empty | ISBLANK({optional}) |
ISNUMBER(value) | Check number | ISNUMBER({input}) |
ISTEXT(value) | Check text | ISTEXT({response}) |
IFBLANK(value, fallback) | Default if empty | IFBLANK({nickname}, {name}) |
COALESCE(...) | First non-empty | COALESCE({mobile}, {home}, {work}) |
SWITCH(val, case1, res1, ...) | Multiple conditions | SWITCH({grade}, "A", 4, "B", 3, 0) |
CHOOSE(index, val1, val2, ...) | Pick by index | CHOOSE({option}, "One", "Two", "Three") |
Common Use Cases
Calculate Total Price
Apply Discount
{subtotal} * (1 - {discount_percent} / 100)
Calculate Tax and Total
// Tax variable
{subtotal} * 0.1
// Total variable (referencing tax)
{subtotal} + {cv_tax}
Conditional Pricing
IF({membership} = "premium", {price} * 0.8, {price})
Grade Calculator
IF({score} >= 90, "A",
IF({score} >= 80, "B",
IF({score} >= 70, "C",
IF({score} >= 60, "D", "F"))))
Full Name
CONCAT({first_name}, " ", {last_name})
Email Domain
RIGHT({email}, LEN({email}) - FIND("@", {email}))
Using Computed Variables
In Mentions
Computed variables appear in the mention dropdown alongside form fields. Look for the 📊 icon:
- In Thank You Page content
- In Email notifications (subject, body, reply-to)
- In Redirect URLs
- In Integration payloads
In Conditional Logic
Use computed variables in conditional logic rules:
- Open the Logic tab for a field
- Add a condition
- Select your computed variable from the dropdown
- Set the comparison operator and value
Example: Show a field only when total is over $100:
- Field:
cv_total
- Condition:
greater_than
- Value:
100
Variable Dependencies
Computed variables can reference other computed variables:
// cv_subtotal
{price} * {quantity}
// cv_tax (references cv_subtotal)
{cv_subtotal} * {tax_rate}
// cv_total (references both)
{cv_subtotal} + {cv_tax}
Circular Dependencies: The system automatically detects and prevents circular references. Variable A cannot reference Variable B if B already references A (directly or indirectly).
Technical Details
Evaluation Timing
| Context | When Evaluated |
|---|
| Form fill | Live, as field values change |
| Conditional logic | Before rendering each field |
| Thank you page | After submission |
| Email notifications | When email is sent |
| Integrations | When integration runs |
Data Storage
Computed variable values are not stored in submission records. They are calculated on-demand when needed. This ensures:
- Always up-to-date calculations
- Smaller database storage
- Formula changes affect past submissions when viewed
Error Handling
If a formula cannot be evaluated (e.g., division by zero, missing field), it returns null. Use IFBLANK() or COALESCE() to provide fallback values:
IFBLANK({cv_calculation}, "N/A")
Best Practices
Naming: Use descriptive names like “Total Price” or “Shipping Cost” rather than generic names like “Calculation 1”.
Validation: Test your formulas with sample data using the preview feature before saving.
Modularity: Break complex calculations into smaller variables that reference each other. This makes formulas easier to understand and debug.
Performance: While computed variables are efficient, avoid extremely complex chains of 10+ interdependent variables for best performance.
