Formula Calculator
Turn a quiz into an interactive calculator: mortgage, ROI, calories, renovation cost — anything.
Updated: April 2026
What is the Formula Calculator#
The Formula Calculator is two special step types in the quiz builder:
Formula (input step)
The visitor enters numeric data: loan amount, room area, number of employees. Supports sliders, number fields, ranges and percentages.
Result (result step)
Automatically calculates an expression from the entered data and shows the result: monthly payment, ROI, calorie intake, etc.
All calculations happen directly in the browser — answers appear instantly, without any server request.
The Formula Calculator is available from the Comfort plan. Comfort+
Features by Plan#
| Feature | Standard | Comfort | Premium |
|---|---|---|---|
| Formula steps per quiz | — | up to 3 | up to 10 |
| Basic operators (+ − × ÷ % ()) | — | ✅ | ✅ |
| Advanced operators (^ sqrt abs round min max if) | — | — | ✅ |
| AI Formula Generator | — | 10 req/hr | 30 req/hr |
| Conditional messages | — | up to 3 | unlimited |
| Calculator templates | — | 10 basic | 30+ by niche |
| Multiple result blocks (MultiResult) | — | — | up to 5 |
| Benchmark comparison | — | — | ✅ |
| AI comment on result | — | — | ✅ |
| PDF download | — | — | ✅ |
Quick Start — from a Template#
The fastest way is to use a ready-made calculator template:
- Click "+ New Quiz" on the main page.
- Switch to the "Calculator" tab in the template gallery.
- Choose a suitable template and click "Use".
- Edit the fields, formulas and texts to match your product.
Available calculator templates:
| Plan | Category | Templates |
|---|---|---|
| Comfort+ | Finance | Mortgage calculator, Compound interest, Savings |
| Comfort+ | Real estate | Rental yield, Renovation budget, Price per m² |
| Comfort+ | Automotive | Fuel savings, Maintenance cost |
| Comfort+ | E-commerce / Health | Discount, Calorie deficit |
| Premium | Automotive | Car loan, Lease vs buy |
| Premium | Business | Profit margin, CAC, LTV, Break-even, Freelance rate |
| Premium | Health / Travel | BMI, Holiday budget |
| Premium | Crypto / Ads / Logistics | Crypto profit, Ad budget, Shipping cost |
The first 10 templates are available on Comfort. All 30+ niche templates unlock on Premium. Premium
Formula Step — Input Fields#
Add a Formula step in the builder. In the step editor configure the fields the visitor will fill in.
Field Types
| Type | What the visitor enters | Example |
|---|---|---|
| Number | Any numeric value | Loan amount: 500,000 |
| Slider | Value via a slider with min/max | Term: ——●—— 15 years |
| Percentage (%) | Value from 0 to 100 | Rate: 12.5% |
| Currency | Number with a currency symbol | $ 25,000 |
| Range | Two sliders: min and max | Budget from $100,000 to $500,000 |
Field Settings
- Variable name — Latin letters without spaces (e.g.
loan_amount). Used in the formula. - Label — text the visitor sees ("Loan Amount").
- Min / Max / Step — constraints for the slider or number field.
- Default value — pre-filled value.
- Prefix / Suffix — symbols around the value (₴, $, m², kg).
- Required — the visitor cannot proceed without filling in this field.
For Range fields two variables are available in the formula: name_min and name_max. For example, a field called budget → variables budget_min and budget_max.
Formula#
On the Result step open the "Formula Result" block — this is where the visual formula builder is located.
Visual Block Builder
The formula is assembled from coloured chip-blocks — no need to type text manually. Three sections at the bottom of the editor:
- Variables — buttons with the field names from the Formula step (e.g.
loan_amount,rate). Click to add to the formula. - Operators — basic (
+−×÷%()) available from Comfort. Advanced (^and math functions) — Premium only. - Number — type a constant and click "+" to add a numeric block (e.g.
100,1200).
Blocks on the canvas can be dragged to reorder. The "⌫" button removes the last block; "×" on a chip removes that specific block.
Below the canvas a live preview (orange card) appears in real time, or an error message (red card) if the formula is invalid. This lets you see immediately whether the formula is correct — without pressing "Check".
Syntax
| Operator / Function | Plan | Meaning | Example |
|---|---|---|---|
| + − × ÷ | Comfort+ | Basic arithmetic | principal × rate ÷ 12 |
| ( ) | Comfort+ | Grouping | (a + b) × c |
| % | Comfort+ | Percentage / remainder | score % 100 |
| ^ | Premium | Exponentiation | 1.05 ^ 12 |
| sqrt(x) | Premium | Square root | sqrt(area) |
| abs(x) | Premium | Absolute value | abs(profit − cost) |
| round(x) | Premium | Round | round(result) |
| min(a, b) | Premium | Smaller of two | min(budget, cost) |
| max(a, b) | Premium | Larger of two | max(0, profit) |
| if(cond, a, b) | Premium | Conditional expression | if(score > 50, 1, 0) |
Formula Examples
| Calculator | Formula |
|---|---|
| Mortgage (monthly payment) | loan_amount × (rate ÷ 12) ÷ (1 − (1 + rate ÷ 12) ^ (−term × 12)) |
| ROI (%) | (revenue − cost) ÷ cost × 100 |
| Daily calories | weight × 10 + height × 6.25 − age × 5 + 5 |
| Renovation cost per m² | area × price_per_sqm + fixed_costs |
| Payback period | investment ÷ monthly_profit ÷ 12 |
The formula does not support JavaScript code or string values. The if() function is available on Premium only. For conditional logic without Premium use Conditional Messages (described below).
AI Formula Generator#
Comfort+Click the "AI Formula Builder" button in the formula editor — describe in plain language what you want to calculate and AI will generate the formula automatically.
- On Comfort — up to 10 requests per hour.
- On Premium — up to 30 requests per hour.
AI sees your variable names — the more descriptive the field names, the better the generated formula. For example, loan_amount is clearer than field1.
Result Format#
For each result block specify how to display the computed value:
| Format | Example result |
|---|---|
| Integer | 12,450 |
| Decimal | 12,450.75 |
| Currency (₴, $, €) | $ 12,450 |
| Percentage | 87.5% |
Additionally configurable: decimal places, thousands separator, prefix and suffix around the value.
Show Input Details (Breakdown)
Enable the "Show Details" toggle in the result block — below the numeric value all field values entered by the visitor are displayed. For example: "Property value: 3,000,000 · Down payment: 20%". Useful for calculators where transparency of the calculation matters.
Saving Changes
The result block editor has its own "Save" button. Changes are not applied automatically — click "Save" to confirm. If you close the editor with unsaved changes the system will ask for confirmation.
Conditional Messages#
Comfort+Below the numeric result you can show personalised text depending on the value. For example: "Excellent ROI!" or "The payback period exceeds the recommended threshold — consider other options".
| Plan | Message limit |
|---|---|
| Comfort | up to 3 messages per result block |
| Premium | unlimited |
How to Set Up
- In the result block click "+ Add Message".
- Enter a condition in the field — use
resultto reference the computed value. For example:result >= 20orresult < 0. - Enter the message text that the visitor will see.
- Optionally add a CTA button with a link (e.g. "Get a consultation").
The first message whose condition is met is shown. If none match — no message is shown.
Multiple Result Blocks#
PremiumA single Result step can show multiple independent calculations simultaneously. For example:
- Monthly payment and Total overpayment for a mortgage calculator.
- ROI and Payback period for a B2B calculator.
- Daily calories and Calorie deficit for weight loss.
Each block has its own formula, format, conditional messages, AI comment and benchmark. On Premium up to 5 result blocks are available. On Comfort and Standard this feature is unavailable (one standard result).
Benchmark Comparison#
PremiumDisplays a progress bar showing where the visitor's result sits relative to a reference (market average) value.
- Reference value — enter manually or click "Auto" to let the system calculate the median from all real responses.
- Label — caption below the progress bar (e.g. "Market average").
The "Auto" button becomes useful once your calculator has collected a few dozen responses — it automatically calculates the median.
AI Comment on Result#
PremiumFor each result block you can enable an AI comment — a personalised text conclusion generated by Claude based on the visitor's specific value.
Settings
- Enable the "AI Comment" toggle in the result block.
- Choose a tone: Professional, Friendly, Direct or Motivational.
- The comment is generated automatically after the visitor sees their result. It takes into account the specific value, format and benchmark.
Example AI comment for a mortgage calculator:
"A monthly payment of $1,850 represents approximately 37% of the average household income in your region. Financial advisors recommend keeping housing costs below 30–35% of income — consider increasing your down payment or extending the loan term."
PDF Download#
PremiumOn the result step the visitor can download the results as a PDF document. The PDF contains:
- Quiz title and generation date.
- All result blocks with computed values.
- Breakdown of entered data.
- AI comment (if enabled).
- Benchmark progress bar.
The PDF is generated directly in the browser — no data is sent to the server. The file is automatically named after the quiz title.
How to Enable
- Open the Result step editor in the builder.
- Enable the "PDF Export" toggle in the step's general settings.
- A "Download PDF" button will appear on the result step for all visitors.
Calculator Analytics#
Comfort+In the Analytics section, quizzes with a Formula step get two additional blocks:
Value distribution
Histogram and statistics (mean, median, P25, P75) for each numeric field. Shows how the data entered by visitors is distributed.
Impact on completion
Correlation between field values and quiz completion rate. Helps identify which numeric ranges have the lowest conversion.
FAQ#
Can I use a formula without a Formula step?
No. The formula references variables from a specific Formula step. Without it there is no source of numeric data for the calculation.
What if the visitor enters an invalid value?
Number and Slider fields only accept numeric values. If the formula result cannot be computed (e.g. division by zero) — the result block is not shown.
Are conditional expressions (if) supported in the formula?
The function if(condition, if_true, if_false) is available on Premium. On Comfort use Conditional Messages to show different text depending on the value.
How many Formula steps can I add to one quiz?
On Comfort — up to 3 steps. On Premium — up to 10 steps. On Standard, Formula steps are unavailable.
Is there a limit on formula complexity?
The maximum expression length is 500 characters. This is sufficient for any real-world calculator. For security the formula cannot contain JavaScript code, system calls or access to browser APIs.