Notes from building a living calculator
Vertical deep-dives, founder writing, and what we’re learning modeling real startup costs for indie operators.
The five rules every house flipper runs (and how our calculator scores them)
The 70% rule is the famous one, but four other rules of thumb matter just as much. Here's what each one tests, why it exists, and how to use the StartupLenz house-flipping calculator to score your own deal.
Read →How much does it cost to start a power washing business in 2026?
How much does it really cost to start a power washing business in 2026? Full breakdown including the rig, the truck, chemicals, insurance, and the chemistry-and-route math nobody else shows you.
Read →How much does it cost to start a food truck in 2026?
How much does it really cost to start a food truck in 2026? Full breakdown including the truck itself, permits, commissary, equipment, insurance, and the location-mix math nobody else shows you.
Read →How much does it cost to start a cleaning business in 2026?
How much does it really cost to start a cleaning business in 2026? Full breakdown including supplies, insurance, bonding, marketing, and the job-type math nobody else shows you.
Read →How much does it cost to start a candle business in 2026?
How much does it really cost to start a candle business in 2026? Full breakdown including materials, vessels, fragrance oils, the Etsy fees most articles ignore, and the channel math nobody else shows you.
Read →How much does it cost to start a slime business in 2026?
How much does it really cost to start a slime business in 2026? Full breakdown — materials, packaging, fees, hidden costs, and the channel math nobody else shows you.
Read →Most startup cost calculators are wrong
Static defaults, no channel mix, no vertical-specific levers. Why the cost calculator that comes up first on Google is probably misleading you, and what a calculator should actually do.
Read →Why we built StartupLenz
StartupLenz started as a slime-brand spreadsheet at our kitchen table. Here's the longer version of why it grew into ten verticals, and what makes a 'living calculator' different from every other cost tool you've opened.
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