Guides
Every guide states its formula, works one example through end to end, and lists what it leaves out. Where a free calculator does the same arithmetic, it is linked from the guide.
- Airbnb & Short-Term Rentals
How to calculate Airbnb profit
Revenue is the easy half. Profit needs the platform's cut, the turnover costs that scale with bookings, and the fixed costs that arrive whether or not anyone stays.
- Construction
How to price a construction job
Build the cost up in the order it is actually incurred, then add markup, and know that the markup you added is not the margin you earned.
- Real Estate & Landlords
How to calculate rental property ROI
Cap rate and cash-on-cash return answer different questions, and a property can look strong on one while losing money every month on the other.
- Real Estate & Landlords
Rental property spreadsheet: free template vs. what you actually need to track
A free template gets you a grid with column headers. It doesn't get you arrears you can see, repairs split from capital improvements, or a number you can hand to an accountant without rebuilding it first.
- Small Business
Markup vs margin: why they are not the same number
Adding 30% to cost does not earn a 30% margin. It earns 23%. The gap is small on paper and large across a year.
- Small Business
How to calculate your break-even point
Break-even is not about covering costs with revenue. It is about how much of each sale is left after the costs that grow with it.
- Construction
How to calculate labor burden
The wage is the smallest part of what an hour of labor costs you, and billing against the wage is how a busy year ends with no money in it.
- Construction
How much contingency to add to a bid
A blanket percentage is a habit, not an assessment. Contingency should be sized against what you could not inspect.
- Construction
What to charge for a change order
A change order is not a small job at your normal rate. It interrupts work that was already sequenced, and the interruption is the part that goes unbilled.
- Construction
Why renovation cost per square foot misleads
Two jobs of identical area can differ five times in cost. Area is a comparison unit, not an estimating one.
- Real Estate & Landlords
The 1% rule, and the two places it breaks
A screening shortcut that works well for sorting a list and badly for deciding anything, because it ignores the two costs that vary most between properties.
- Real Estate & Landlords
How much vacancy actually costs
Lost rent is the visible half. The turnover that caused it costs nearly as much again, and most models count neither properly.
- Real Estate & Landlords
How to compare two rental properties
The cheaper property is not the better deal often enough that comparing on price is close to guessing.
- Airbnb & Short-Term Rentals
How to set an Airbnb nightly rate
Copying the flat down the road prices your listing against their mortgage. Work backwards from what you need the year to produce instead.
- Airbnb & Short-Term Rentals
Break-even occupancy is a monthly number, not an annual one
An annual average that clears break-even can still contain four months that lose money, and those are the months that empty the account.
- Airbnb & Short-Term Rentals
What an Airbnb cleaning fee should cover
Most hosts believe the cleaning fee makes a small profit. Once the deep clean is included, a lot of them are running it at a loss.
- Small Business
How to calculate inventory turnover
Stock is cash you have already spent and cannot use. Turnover tells you how long it stays that way.
- Small Business
How to forecast cash flow when profit is not the problem
Profitable businesses fail on timing. A month can earn nine thousand and still leave you five thousand short.
- Small Business
How to set an hourly rate you can actually live on
Dividing a target salary by 2,080 hours produces a rate that guarantees you earn less than the salary you wanted.
- Freelancers
How much to set aside for tax when your income is lumpy
A flat quarterly transfer under-reserves in your good quarters, which are exactly the quarters that generate the bill.
- Wedding
How to set a wedding budget from the guest count
One decision sets most of the cost, and it is not the venue. Nearly sixty percent of a typical budget moves with how many people you invite.
- Wedding
How to compare wedding vendor quotes
The cheapest quote is often the most expensive per hour. Comparing totals compares different jobs.
- Homestead & Chicken
How much does it cost to keep chickens
Feed is the number people ask about and the coop is the number that decides whether it was worth it.
- Homestead & Chicken
How to calculate cost per egg
The same flock produces eggs at $3.95 or $4.93 a dozen depending on one decision about the coop.
- Homestead & Chicken
When does a backyard flock break even
Against cheap supermarket eggs, roughly never. Against the eggs most keepers would actually buy, about two years.
- Creators
How to price a sponsored post
The deliverable is the small part. Usage rights and exclusivity are where the money is, and they are usually given away for nothing.
- Creators
How to track brand deal income
The most valuable thing in the log is the deals you turned down, because they are the only record of what your market really pays.
- AI & Productivity
How to calculate AI API costs before they surprise you
Output tokens usually cost several times what input tokens do, so the cheapest way to raise a bill is to make the model talk more.
- AI & Productivity
How to calculate automation ROI honestly
Most automations that fail the arithmetic fail on the same thing: the task was not frequent enough to matter.
- AI & Productivity
What AI tools actually cost a team
Nobody escalates a twenty dollar decision, which is exactly why these things are priced at twenty dollars.
- AI & Productivity
How to test whether one prompt is really better than another
Forty examples cannot tell an 85% prompt from a 75% one, and forty examples is what almost everybody uses.
- Small Business
How to calculate gross margin by product
A blended margin is an average of things that have nothing in common, and it hides which products are carrying the business.
- Small Business
What a price increase actually buys you
A five percent rise lets you lose eight percent of your customers and stay level. A ten percent discount needs twenty two percent more of them.
- Real Estate & Landlords
How to calculate cash-on-cash return
The formula is trivial. Almost every mistake happens in the denominator, and it always flatters the deal.
- Real Estate & Landlords
How much to budget for maintenance and capital expenditure
The percentage rules of thumb come out at half what a component-by-component estimate does, and the components are the ones that actually break.
- Real Estate & Landlords
How to screen a tenant, and what skipping it costs
Full screening costs around $180. One bad tenancy costs around $14,300. That ratio is the entire argument.
- Real Estate & Landlords
Is a property manager worth 8%
The honest way to answer is to work out what self-managing pays you per hour, and then decide whether you want that job.
- Construction
How to do a material takeoff
Measure, deduct openings, add waste, then round up to what the supplier actually sells. The last step is the one that gets skipped.
- Construction
What bidding costs you, and why bidding less can earn more
At one win in five, every job you take has already absorbed the cost of four you did not.
- Airbnb & Short-Term Rentals
How to budget for furnishing a short let
The setup cost is the number everyone plans for. The replacement cycle is the one that decides whether the listing stays profitable.
- Airbnb & Short-Term Rentals
What the platform fee actually costs you
The two fee structures cost the host different amounts and show the guest very different prices, and the cheaper one for you is the more expensive one for them.
- Airbnb & Short-Term Rentals
Short let or long let: the arithmetic and the hourly rate
A short let can earn two and a half times the income and consume five hundred hours a year. The right comparison is per hour, not per year.
- Small Business
How to set a reorder point
Reordering when you notice the shelf is empty means you were already out for a week and did not know.
- Small Business
How much runway do you have, counting the lumpy months
Cash divided by average burn is the number everybody quotes, and it is wrong whenever a large payment is due before the money runs out.
- Construction
How to price emergency and callout work
A two hour callout consumes four and a half hours of your day. Billing two of them is how emergency work loses money.
- Wedding
When wedding money is actually due
Couples plan the total and almost nobody plans the timing, which is why nearly two thirds of the budget falls in the last month.
- Wedding
How many wedding guests can you actually afford
Work it out from the budget rather than from the list, and every $1,190 you spend elsewhere costs you ten people.
- Freelancers
How to price a fixed fee project
A fixed fee moves the risk of overrunning onto you and the reward for working efficiently as well. Price it so both are covered.
- Freelancers
What a late-paying client actually costs
The financing cost of being paid 38 days late is $52. The chasing costs $198, and nobody invoices for that.
- Homestead & Chicken
How much space chickens need, and what happens when they do not have it
Overcrowding does not look like overcrowding. It looks like feather pecking, a mite outbreak and hens that stop laying.
- Creators
How to put a defensible number on your audience
Two ways to price a post arrive at almost the same figure, which is what makes the figure defensible in a negotiation.
- Small Business
Spreadsheet templates, calculators and trackers: what actually matters
Most template pages sell you on tabs and colour. None of that predicts whether you will still be using the thing in March.
- Small Business
How to choose spreadsheet templates, calculators and trackers: a practical checklist
Two templates that look almost identical can differ by a full grade once you score them against what you actually need, not against each other's screenshots.