{"success":true,"version":"v1","request":{"tool":"list_calculators","category":"business"},"result":{"entity_type":"calculator_list","status":"completed","count":17,"calculators":[{"calculator_id":"ad-metrics","entity_type":"calculator","name":"Ad Metrics Calculator (CPM, CPC, CTR, CPA)","category":"business","tool_name":"calculate_ad_metrics","description":"Computes the standard paid-advertising metrics cost per mille (CPM), cost per click (CPC), click-through rate (CTR), cost per acquisition (CPA) and click-to-conversion rate from campaign spend, impressions, clicks and conversions.","use_when":"You have raw campaign totals (spend, impressions, clicks, optionally conversions) and need CPM, CPC, CTR, CPA or conversion rate, e.g. to compare channels or report performance.","do_not_use_when":"You need revenue-based efficiency (use roas), publisher-side earnings from RPM (use ad-revenue), or conversion rate from site visitors rather than ad clicks (use conversion-rate).","required_inputs":["spend","impressions","clicks"],"optional_inputs":["conversions"],"urls":{"html":"https://tttkmbb.com/business/ad-metrics","markdown":"https://tttkmbb.com/business/ad-metrics.md","schema":"https://tttkmbb.com/api/v1/calculators/ad-metrics","api":"https://tttkmbb.com/api/v1/calculate/ad-metrics"}},{"calculator_id":"ad-revenue","entity_type":"calculator","name":"Ad Revenue Calculator (RPM)","category":"business","tool_name":"estimate_ad_revenue","description":"Estimates publisher ad earnings per day, month (365/12 days) and year from page views and RPM (revenue per 1,000 impressions), optionally with several ad units per page and a fill rate, and solves for the page views needed to reach a target monthly revenue.","use_when":"You run a website, app or video channel and want to project ad income from traffic and RPM, or find how much traffic a revenue goal requires.","do_not_use_when":"You are the advertiser buying impressions (use ad-metrics for CPM/CPC/CPA) or need revenue from sales rather than ads (use conversion-rate or roas).","required_inputs":["page_views_per_day","rpm"],"optional_inputs":["ads_per_page","fill_rate_percent","target_monthly_revenue"],"urls":{"html":"https://tttkmbb.com/business/ad-revenue","markdown":"https://tttkmbb.com/business/ad-revenue.md","schema":"https://tttkmbb.com/api/v1/calculators/ad-revenue","api":"https://tttkmbb.com/api/v1/calculate/ad-revenue"}},{"calculator_id":"conversion-rate","entity_type":"calculator","name":"Conversion Rate Calculator","category":"business","tool_name":"calculate_conversion_rate","description":"Computes the conversion rate (conversions / visitors × 100), conversions per 1,000 visitors and visitors per conversion, and the number of visitors required to reach a target number of conversions at the same rate.","use_when":"You have visitor and conversion counts for a page, funnel step, email or campaign and need the rate or the traffic a conversion goal requires.","do_not_use_when":"You are comparing two variants for statistical significance (use ab-test-significance) or need cost-based metrics such as CPA (use ad-metrics).","required_inputs":["visitors","conversions"],"optional_inputs":["target_conversions"],"urls":{"html":"https://tttkmbb.com/business/conversion-rate","markdown":"https://tttkmbb.com/business/conversion-rate.md","schema":"https://tttkmbb.com/api/v1/calculators/conversion-rate","api":"https://tttkmbb.com/api/v1/calculate/conversion-rate"}},{"calculator_id":"ab-test-significance","entity_type":"calculator","name":"A/B Test Significance Calculator","category":"business","tool_name":"calculate_ab_test_significance","description":"Tests whether a variant's conversion rate differs from the control's using the pooled two-proportion z-test, and reports both rates, absolute and relative lift, z-score, two-sided p-value, a confidence interval for the difference and the sample size needed per variant to detect the observed lift with 80 % power.","use_when":"You have visitors and conversions for a control and a variant (A/B test, split test, email test) and need to know whether the difference is statistically significant.","do_not_use_when":"The metric is a mean (revenue per user, time on page) rather than a conversion proportion, or there are more than two variants (use a chi-square or multiple-comparison procedure).","required_inputs":["control_visitors","control_conversions","variant_visitors","variant_conversions"],"optional_inputs":["confidence_level_percent"],"urls":{"html":"https://tttkmbb.com/business/ab-test-significance","markdown":"https://tttkmbb.com/business/ab-test-significance.md","schema":"https://tttkmbb.com/api/v1/calculators/ab-test-significance","api":"https://tttkmbb.com/api/v1/calculate/ab-test-significance"}},{"calculator_id":"cac-ltv","entity_type":"calculator","name":"CAC and LTV Calculator","category":"business","tool_name":"calculate_cac_ltv","description":"Computes customer acquisition cost from marketing spend and new customers, customer lifetime value from monthly revenue per customer, gross margin and monthly churn (lifetime = 1 / churn), plus the LTV:CAC ratio and CAC payback period in months.","use_when":"You need SaaS or subscription unit economics: how much a customer costs to acquire, what they are worth over their lifetime, and how the two compare.","do_not_use_when":"Customers buy once rather than recur (LTV then equals margin per order × repeat purchases) or you only need the churn rate itself (use churn-rate).","required_inputs":["marketing_spend","new_customers","monthly_revenue_per_customer","monthly_churn_percent"],"optional_inputs":["gross_margin_percent"],"urls":{"html":"https://tttkmbb.com/business/cac-ltv","markdown":"https://tttkmbb.com/business/cac-ltv.md","schema":"https://tttkmbb.com/api/v1/calculators/cac-ltv","api":"https://tttkmbb.com/api/v1/calculate/cac-ltv"}},{"calculator_id":"churn-rate","entity_type":"calculator","name":"Churn Rate Calculator","category":"business","tool_name":"calculate_churn_rate","description":"Computes the customer churn rate for a period from customers at the start and customers lost, the retention rate, the ending customer count and net growth including customers gained, the annualised churn rate and the implied average customer lifetime (1 / churn).","use_when":"You track subscribers, members or accounts over a month, quarter or year and need churn, retention or expected customer lifetime.","do_not_use_when":"You need revenue churn in currency terms or MRR projections (use mrr-growth) or the full acquisition economics (use cac-ltv).","required_inputs":["customers_at_start","customers_lost"],"optional_inputs":["customers_gained","period"],"urls":{"html":"https://tttkmbb.com/business/churn-rate","markdown":"https://tttkmbb.com/business/churn-rate.md","schema":"https://tttkmbb.com/api/v1/calculators/churn-rate","api":"https://tttkmbb.com/api/v1/calculate/churn-rate"}},{"calculator_id":"paypal-fee","entity_type":"calculator","name":"PayPal Fee Calculator","category":"business","tool_name":"calculate_paypal_fee","description":"Computes the PayPal fee and net amount for a US sale using the published US merchant rates (as of 2026-09: PayPal Checkout 3.49 % + $0.49, standard card 2.99 % + $0.49, goods & services 2.99 %, QR code 2.29 % + $0.09, +1.50 % international), or the gross amount to charge to net a target; rates can be overridden.","use_when":"You sell or invoice through PayPal in the US and need the fee, what you will receive, or what to charge so that you receive a specific amount.","do_not_use_when":"The account is outside the US or uses micropayment, non-profit or custom negotiated rates (enter those with rate_percent and fixed_fee), or you need Stripe (stripe-fee), eBay (ebay-fee) or Etsy (etsy-fee) fees.","required_inputs":["amount"],"optional_inputs":["transaction_type","international","rate_percent","fixed_fee","solve_for"],"urls":{"html":"https://tttkmbb.com/business/paypal-fee","markdown":"https://tttkmbb.com/business/paypal-fee.md","schema":"https://tttkmbb.com/api/v1/calculators/paypal-fee","api":"https://tttkmbb.com/api/v1/calculate/paypal-fee"}},{"calculator_id":"stripe-fee","entity_type":"calculator","name":"Stripe Fee Calculator","category":"business","tool_name":"calculate_stripe_fee","description":"Computes the Stripe processing fee and net payout for a US card payment using Stripe's published standard pricing (as of 2026-09: 2.9 % + $0.30 per successful domestic card charge, +1.5 % international cards, +1 % currency conversion, +0.5 % manually entered cards), or the gross amount to charge to net a target.","use_when":"You charge customers through Stripe and need the fee on a payment, the payout after fees, or the price to charge so that you receive a specific amount.","do_not_use_when":"Your account has custom or interchange-plus pricing or is outside the US (enter your rates with rate_percent and fixed_fee), or the payment goes through PayPal (paypal-fee).","required_inputs":["amount"],"optional_inputs":["card_origin","currency_conversion","manually_entered","rate_percent","fixed_fee","solve_for"],"urls":{"html":"https://tttkmbb.com/business/stripe-fee","markdown":"https://tttkmbb.com/business/stripe-fee.md","schema":"https://tttkmbb.com/api/v1/calculators/stripe-fee","api":"https://tttkmbb.com/api/v1/calculate/stripe-fee"}},{"calculator_id":"ebay-fee","entity_type":"calculator","name":"eBay Fee Calculator","category":"business","tool_name":"calculate_ebay_fee","description":"Computes eBay's final value fee and net proceeds for a US sale in most categories (as of 2026-09: 13.6 % of the total sale amount up to $7,500 per item plus 2.35 % of the portion above, plus $0.40 per order or $0.30 for orders of $10 or less), with optional insertion fee and category-rate overrides.","use_when":"You sell on eBay.com without an eBay Store in a standard category and want the fee, net proceeds or effective fee rate for a listing price.","do_not_use_when":"The item is in a category with different rates (books, movies, music, coins, trading cards, some vehicle and business categories) unless you enter that rate, the seller has an eBay Store subscription, or you sell on another eBay site; promoted-listing ad fees are not included.","required_inputs":["item_price"],"optional_inputs":["shipping_charged","final_value_fee_percent","upper_tier_percent","tier_threshold","per_order_fee","insertion_fee"],"urls":{"html":"https://tttkmbb.com/business/ebay-fee","markdown":"https://tttkmbb.com/business/ebay-fee.md","schema":"https://tttkmbb.com/api/v1/calculators/ebay-fee","api":"https://tttkmbb.com/api/v1/calculate/ebay-fee"}},{"calculator_id":"etsy-fee","entity_type":"calculator","name":"Etsy Fee Calculator","category":"business","tool_name":"calculate_etsy_fee","description":"Computes Etsy's fees and net proceeds for a US sale using the published fee schedule (as of 2026-09: $0.20 listing fee, 6.5 % transaction fee on item price plus shipping, 3 % + $0.25 Etsy Payments processing fee on the total, optional 12–15 % Offsite Ads fee); every rate can be overridden.","use_when":"You sell on Etsy.com from a US bank account and need the fees, net proceeds or effective fee rate for a listing price and shipping charge.","do_not_use_when":"Your shop is outside the US (payment processing rates and regulatory operating fees differ by country; override the processing inputs), or you need eBay (ebay-fee), PayPal (paypal-fee) or Stripe (stripe-fee) fees.","required_inputs":["item_price"],"optional_inputs":["shipping_charged","transaction_fee_percent","payment_processing_percent","payment_processing_fixed_fee","listing_fee","offsite_ads_fee_percent"],"urls":{"html":"https://tttkmbb.com/business/etsy-fee","markdown":"https://tttkmbb.com/business/etsy-fee.md","schema":"https://tttkmbb.com/api/v1/calculators/etsy-fee","api":"https://tttkmbb.com/api/v1/calculate/etsy-fee"}},{"calculator_id":"burn-rate-runway","entity_type":"calculator","name":"Burn Rate and Runway Calculator","category":"business","tool_name":"calculate_burn_rate_runway","description":"Computes gross burn, net burn (expenses minus revenue) and the runway in months from a cash balance, and the projected date the cash runs out when a start date is given.","use_when":"You are a startup or project with a fixed cash pile and want to know how long it lasts at current spending and revenue.","do_not_use_when":"Revenue or costs change month to month (model each month separately) or you need a loan payoff or savings timeline (use debt-payoff or savings-goal).","required_inputs":["cash_balance","monthly_expenses"],"optional_inputs":["monthly_revenue","start_date"],"urls":{"html":"https://tttkmbb.com/business/burn-rate-runway","markdown":"https://tttkmbb.com/business/burn-rate-runway.md","schema":"https://tttkmbb.com/api/v1/calculators/burn-rate-runway","api":"https://tttkmbb.com/api/v1/calculate/burn-rate-runway"}},{"calculator_id":"freelance-hourly-rate","entity_type":"calculator","name":"Freelance Hourly Rate Calculator","category":"business","tool_name":"calculate_freelance_hourly_rate","description":"Derives the hourly and daily rate a freelancer must bill to reach a target annual income after business overhead and a tax reserve, given billable hours per week and weeks off per year.","use_when":"You are setting or checking a freelance, consulting or contractor rate and know the income you want to keep.","do_not_use_when":"You want to convert an employee salary to hourly pay without overhead or tax (use salary-converter) or count hours worked (use work-hours).","required_inputs":["target_annual_income","billable_hours_per_week"],"optional_inputs":["weeks_off_per_year","overhead_percent","tax_reserve_percent","hours_per_day"],"urls":{"html":"https://tttkmbb.com/business/freelance-hourly-rate","markdown":"https://tttkmbb.com/business/freelance-hourly-rate.md","schema":"https://tttkmbb.com/api/v1/calculators/freelance-hourly-rate","api":"https://tttkmbb.com/api/v1/calculate/freelance-hourly-rate"}},{"calculator_id":"eoq","entity_type":"calculator","name":"Economic Order Quantity (EOQ) Calculator","category":"business","tool_name":"calculate_economic_order_quantity","description":"Computes the economic order quantity that minimises the sum of annual ordering and holding costs (Harris–Wilson formula √(2DS/H)), plus orders per year, days between orders and the resulting annual costs.","use_when":"You reorder a product with steady demand and want the order size that balances ordering cost against holding cost.","do_not_use_when":"Demand is highly variable or seasonal, quantity discounts apply, or the item is produced in-house at a finite rate (use the economic production quantity model); for when to order, use reorder-point.","required_inputs":["annual_demand_units","ordering_cost_per_order","holding_cost_per_unit_per_year"],"optional_inputs":["unit_cost","working_days_per_year"],"urls":{"html":"https://tttkmbb.com/business/eoq","markdown":"https://tttkmbb.com/business/eoq.md","schema":"https://tttkmbb.com/api/v1/calculators/eoq","api":"https://tttkmbb.com/api/v1/calculate/eoq"}},{"calculator_id":"reorder-point","entity_type":"calculator","name":"Reorder Point Calculator","category":"business","tool_name":"calculate_reorder_point","description":"Computes the inventory level at which to place a new order: average daily demand × lead time plus safety stock, where safety stock is either given directly or derived from a service level and the standard deviation of daily demand (z × σ × √lead time).","use_when":"You need the stock level that triggers a purchase order so that demand during the supplier lead time is covered with a chosen service level.","do_not_use_when":"You need the order size rather than the trigger level (use eoq), or lead time itself varies substantially (the formula would need the lead-time variance term).","required_inputs":["daily_demand_units","lead_time_days"],"optional_inputs":["safety_stock_units","demand_std_dev_daily","service_level_percent"],"urls":{"html":"https://tttkmbb.com/business/reorder-point","markdown":"https://tttkmbb.com/business/reorder-point.md","schema":"https://tttkmbb.com/api/v1/calculators/reorder-point","api":"https://tttkmbb.com/api/v1/calculate/reorder-point"}},{"calculator_id":"roas","entity_type":"calculator","name":"ROAS Calculator","category":"business","tool_name":"calculate_roas","description":"Computes return on ad spend (revenue / ad spend) as a ratio and percentage, the advertising cost of sales (ACoS), and, when the gross margin is given, the break-even ROAS (1 / margin) and the gross profit left after ad spend.","use_when":"You want to judge whether a paid campaign pays for itself: revenue per unit of ad spend and the ROAS needed to break even at your margin.","do_not_use_when":"You need cost per click or per acquisition (use ad-metrics), or a full return on investment with all costs (use roi).","required_inputs":["revenue","ad_spend"],"optional_inputs":["gross_margin_percent"],"urls":{"html":"https://tttkmbb.com/business/roas","markdown":"https://tttkmbb.com/business/roas.md","schema":"https://tttkmbb.com/api/v1/calculators/roas","api":"https://tttkmbb.com/api/v1/calculate/roas"}},{"calculator_id":"sales-commission","entity_type":"calculator","name":"Sales Commission Calculator","category":"business","tool_name":"calculate_sales_commission","description":"Computes the commission on a sale at a flat percentage, or with a two-tier plan where a higher rate applies above a threshold, either marginally (only on the amount above the threshold) or retroactively (on the whole amount), plus the effective rate and the net to the company.","use_when":"You need to pay or check a salesperson's, agent's or affiliate's commission on a deal, including accelerator tiers.","do_not_use_when":"Commission depends on quota attainment across many deals, includes a base salary or draw, or has more than two tiers (compute tiers separately).","required_inputs":["sale_amount","commission_percent"],"optional_inputs":["tier_threshold","tier_commission_percent","tier_mode"],"urls":{"html":"https://tttkmbb.com/business/sales-commission","markdown":"https://tttkmbb.com/business/sales-commission.md","schema":"https://tttkmbb.com/api/v1/calculators/sales-commission","api":"https://tttkmbb.com/api/v1/calculate/sales-commission"}},{"calculator_id":"mrr-growth","entity_type":"calculator","name":"MRR Growth Calculator","category":"business","tool_name":"predict_mrr_growth","description":"Projects monthly recurring revenue after n months of compound growth from a starting MRR and a monthly growth rate (given directly or derived from new, expansion and churned MRR), and reports the resulting ARR, total growth, the equivalent annual growth rate and the doubling time.","use_when":"You run a subscription business and want to see where MRR lands after a number of months at the current growth rate, or convert a monthly rate into an annual one.","do_not_use_when":"Growth is in absolute amounts rather than a percentage each month (use a linear projection), or you need customer-count churn (use churn-rate) or unit economics (use cac-ltv).","required_inputs":["starting_mrr"],"optional_inputs":["monthly_growth_percent","new_mrr","expansion_mrr","churned_mrr","months"],"urls":{"html":"https://tttkmbb.com/business/mrr-growth","markdown":"https://tttkmbb.com/business/mrr-growth.md","schema":"https://tttkmbb.com/api/v1/calculators/mrr-growth","api":"https://tttkmbb.com/api/v1/calculate/mrr-growth"}}]},"timestamp":"2026-09-24T01:53:52Z","next_actions":[],"links":{"docs":"https://tttkmbb.com/calculators.md"}}