REVENUE & GROWTH
What if my business grows?
See what a few more customers or a different price could mean for your recurring revenue.
MRR · ARR
BIG IDEAS. NO MATH DEGREE REQUIRED.
Lay Math.
Make the numbers
make sense.
Less head-scratching. More “oh, I get it.”
Explore the math behind your business, one little
what-if at a time.
THE WHAT-IF SANDBOXLive
A little change. A bigger picture.
Your next “what if” starts here.
0500
$/ mo
$0$200
HERE’S THE BIGGER PICTURE
Monthly recurring revenue MRR
$5,880/ month
Annual recurring revenue ARR
$70,560/ year
No sign-up. No spreadsheets. Just a little clarity.Your figures. Real math.
YOUR BUSINESS, MINUS THE GUESSWORK
Big questions. Useful little tools.
BUSINESS VALUE
What’s my business worth?
Explore earnings, revenue, and asset-based valuations. Get a starting point, not a crystal ball.
SDE · EBITDA · MULTIPLESPRICE & PERSPECTIVE
Is that price the whole story?
Put a company’s share price next to its earnings. Make sense of the ratio behind the number.
PRICE / EARNINGSNET ASSET VALUE
What’s really underneath?
Subtract what’s owed from what’s owned, then see it per share. The math behind funds and holdings.
NAV · PER SHAREGOING PUBLIC
How much does an IPO raise?
Shares offered × offer price. See the headline number and what it does and doesn’t mean.
IPO · OFFER PRICEEVERYDAY MATH
Is 25% off a good deal?
Percentages trip everyone up. See exactly what you save and what you pay.
PERCENT · DISCOUNTSOWNERSHIP
How much do I keep if I sell shares?
Raising money means new shares. See exactly how your ownership percentage changes.
DILUTION · EQUITYPERSONAL FINANCE
What’s my personal net worth?
Add up what you own, subtract what you owe. The single number that sums up your finances.
ASSETS − DEBTSLIFE EVENTS
What will the big day cost?
Weddings, christenings, funerals: guests × per-person cost, plus fixed costs and a cushion.
GUESTS · VENUE · BUFFEREDUCATION
What does a degree really cost?
Bachelor’s, a second degree, or a PhD — every year’s tuition and living costs, added up.
TUITION · YEARS · AIDPRICING
Margin or markup?
A 50% markup isn’t a 50% margin. See gross margin, net margin, and markup side by side.
GROSS · NET · MARKUPBREAK-EVEN
How many sales to break even?
Find break-even in units and in sales dollars, using the two methods accountants use.
UNITS · SALES $PAYDAY
What will I actually take home?
Go from gross salary to net pay, with tax and deductions laid out line by line.
GROSS · NETTAX
How much of my revenue is taxable?
Subtract deductible expenses and allowances, then estimate the tax on what’s left.
TAXABLE · ESTIMATEBORROWING
What will this loan really cost?
See the monthly payment, the total you’ll pay back, and how much of it is interest.
PAYMENT · TOTAL COSTDECIDE
Buy outright, borrow, hire purchase, or lease?
Put cash, a loan, hire purchase, and a lease side by side and see which costs you least over the same years.
CASH · LOAN · HP · LEASEINTEREST
Simple or compound?
Per month, per annum, every three or six months — see how the same rate grows differently.
SIMPLE · COMPOUND · APYINVESTING
What could my money earn?
Start with a lump sum, add a little each month, and see what time and returns can do.
RETURNS · TIMERETIREMENT
Will my savings last?
Turn what you save today into a monthly income for the years after you stop working.
SAVINGS · INCOMESCIENCE
Is 30°C hot or cold?
Fahrenheit to Celsius in one step, with a quick mental shortcut you can use anywhere.
°F · °CEVERYDAY MATH
What time is 19:45?
Turn 24-hour time into a regular clock without counting on your fingers.
24H · AM / PMEVERYDAY MATH
What does my BMI mean?
See the simple formula behind body mass index, and what the number can and can’t tell you.
BMI · WEIGHT ÷ HEIGHT²SCIENCE
How long will the drive take?
Speed, distance, and time — one simple triangle that answers all three.
SPEED · DISTANCE · TIMESCIENCE
Why does ice float?
Density in one division, and why heavy steel ships still float.
MASS ÷ VOLUMESCIENCE
Volts, amps, ohms?
Ohm’s law and electrical power explained with a simple water-pipe picture.
V = I × RSCIENCE
What does my heater cost to run?
Turn the watts on any label into kilowatt-hours and real money on your bill.
WATTS · kWh · COSTSCIENCE
Why does speed matter so much?
Kinetic energy shows why twice as fast means four times the impact.
½ m v²SAFETY
How far until I stop?
See how far your car travels before and during braking — on dry, wet, or icy roads.
REACTION · BRAKINGSAFETY
Am I too close?
Turn the two-second rule into a real distance at your speed.
2-SECOND RULESAFETY
Is my ladder at a safe angle?
The 4-to-1 rule and Pythagoras tell you where to put the feet and how long a ladder you need.
4 : 1 · PYTHAGORASMONEY
What is my car or house worth now?
Depreciation two ways: the same amount each year, or a percentage of what’s left.
STRAIGHT-LINE · DECLININGEVERYDAY MATH
What does servicing cost per mile or km?
Turn your service schedule and repair bills into a simple cost for every mile you drive.
SERVICE · MILESTRAVEL MONEY
What is my money worth there?
One rate turns any amount into another currency — and back the other way.
RATE · REVERSE RATETRAVEL
What time will you land?
Departure time, flight hours, and the zones you cross — arrive knowing the local time.
UTC OFFSETS · ARRIVALSKILLS
How long is 10,000 hours?
The famous mastery number turned into days, weeks, months, and years — at the pace you can actually keep.
HOURS · WEEKS · YEARSUPKEEP
What does raising a child cost?
Baby gear, food, clothes, childcare and school — added up from birth to 18.
MONTHLY · YEARLY · 18 YEARSUPKEEP
What does a pet really cost?
Food, vet visits, insurance and setup for a dog, cat, small pet, or bird — over its whole life.
DOG · CAT · LIFETIMEUPKEEP
What does it cost to keep a car?
Fuel, insurance, servicing and repairs, year after year, with prices rising.
FUEL · INSURANCE · REPAIRSUPKEEP
What does it cost to keep a house?
Bills, repairs, insurance and property tax, plus the big replacements like a roof.
BILLS · REPAIRS · RESERVESHOPPING
Which pack is the better deal?
Compare price per gram, ounce, or item — the sticker price can fool you.
PRICE ÷ SIZEKITCHEN
How do I scale this recipe?
Serves 4, cooking for 7? One multiplier keeps every ratio right.
SERVINGS · RATIODINING OUT
What do I owe on this bill?
Your items, your share of the starters, plus tax and tip — fair to everyone.
SHARE · TAX · TIPTAX
Will a raise push me into a higher tax?
Tax brackets slice by slice — see your marginal and effective rate side by side.
MARGINAL · EFFECTIVEHOME LOAN
Where do my mortgage payments go?
See why early payments are mostly interest, and when you’re really half paid off.
INTEREST · PRINCIPALWORKSHOP
What is 2.375\u2033 in mm?
Decimal inches into millimetres and the nearest fraction on your tape.
IN · MM · 1/16″BUILDING
How much floor, how much concrete?
Split odd rooms into rectangles and triangles, then add depth for concrete.
AREA · VOLUMEDIY
How many tiles do I buy?
Cover the area, add 10\u201315% waste, and round up to whole boxes.
AREA · WASTE · BOXESMIXING
What does 1:4 really mean?
Concentrate and water for any total amount \u2014 and why 1:4 is 20%, not 25%.
PARTS · TOTALHEALTH
How much medicine for this weight?
mg per kg into mL \u2014 for learning, always confirm with a professional.
KG · MG · MLDATA
Why is my average wrong?
Big groups should count more than small ones \u2014 weighted vs simple averages.
WEIGHTED · SIMPLEPAYROLL
What do I owe for part of a month?
Salary or bills for only the days worked or used.
PER DAY · DUESTOCK
How fast does my stock sell?
Cost of goods sold \u00f7 average inventory \u2014 and days on the shelf.
TURNS · DAYSDATA
Is the average misleading me?
See how one huge number drags the mean, while the median stays put.
MEAN · MEDIANPROBABILITY
Positive test \u2014 how worried should I be?
Why a positive for a rare condition is often a false alarm.
BASE RATE · BAYESSURVEYS
Is A really ahead of B?
Margins of error tell you when results are too close to call.
± POINTS · OVERLAPDESIGN
How do I resize without stretching?
Keep width and height in proportion for photos, video, and prints.
16:9 · 4:3SCIENCE
Twice as big \u2014 how much heavier?
Double the size: four times the surface, eight times the weight.
k² · k³INFLATION
What will my money be worth later?
See how rising prices shrink what your money buys, and whether your savings are really keeping up.
BUYING POWER · REAL RETURNSHOPPING
What does Small or Medium mean?
Turn your chest or bust measurement into S, M, L — plus US, UK, and EU numbers.
XS–XXL · US · UK · EUPROFIT
How much profit am I really making?
Gross, operating, and net profit — and what happens if sales rise or fall.
GROSS · OPERATING · NETCASH
Will I run out of cash?
Money in, money out, month by month — with your runway and worst-case scenario.
IN · OUT · RUNWAYCASH
How much free cash is left?
Turn profit into real cash, then subtract what you reinvest in equipment.
OCF − CAPEXPROJECTS
How long will this project take?
Best, likely, and worst case estimates turned into hours, working days, and weeks for your team.
PERT · TEAM · BUFFERSHOPPING
What is my shoe size over there?
Convert between US men’s, US women’s, UK, EU, and foot length in cm.
US · UK · EU · CMFITNESS
What are 10,000 steps?
Steps into kilometres and miles, walking time, and how many days your step goal takes.
STEPS · DISTANCE · TIME LOST IN THE LETTERS?
Business speaks in acronyms.
We speak human.
Unpack the terms you hear. Without the textbook.
HARD MATH. EVERYDAY CLARITY.
Math isn’t just for math people.
It’s for the person building something, pricing something, or wondering “what if?”
Lay Math turns intimidating ideas into things you can see, change, and understand.