InTrendz MediaSystem: nominal

01 // Growth Lab / Proof that can’t be faked

Free marketing calculators.AI made words free. These took work.

The InTrendz Growth Lab is a set of free marketing calculators that run in your browser. Each one applies a proven model from another science, such as epidemiology, pharmacokinetics or queueing theory, to one marketing question about budgets, ad fatigue, referrals, retention, pricing or AI search.

Try one now / Epidemiology

Will your referrals compound or fizzle?

K-factor
0.40

Every 100 users bring in 67 more.

Open the Viral Growth Simulator
New users per referral cycle, starting from 100

K = invites per user × conversion. Below 1, each cycle is smaller than the last. At 1 or above, growth compounds.

Showing 23 of 23 tools

02 // Model tools / Borrowed laws

Sixteen laws, borrowed from other sciences

Why we borrow models
01 // Epidemiology

Viral Growth Simulator

Will referrals compound or fizzle?

SIR model, K = i × c
Runs in your browser
02 // Pharmacokinetics

Adstock and Carryover

How long does this week's spend keep working?

Geometric adstock: A(t) = x(t) + θ × A(t-1)
Runs in your browser
03 // Biochemistry

Budget Saturation Curve

Where does the next dollar stop paying back?

Hill / Michaelis-Menten response
Runs in your browser
04 // Linguistics

AI Answer-Readiness Scorer

Is this passage easy for AI engines to quote?

Flesch reading ease plus answer-block checks
Runs in your browser
05 // Nuclear physics

Ad Fatigue Half-Life

When should a creative be refreshed?

Exponential decay, half-life = ln 2 / λ
Runs in your browser
06 // Diffusion science

Adoption Forecaster

How fast will a launch reach its market?

Bass model (p, q)
Runs in your browser
07 // Actuarial science

LTV and Churn Survival

What is a customer worth month by month?

Survival curve with discounting
Runs in your browser
08 // Telecom queueing

Lead Response Capacity

How many SDRs to reply within 5 minutes?

Erlang C and Little's Law (L = λW)
Runs in your browser
09 // Reliability engineering

Funnel Bottleneck Finder

Which stage costs the most revenue?

Series system: total = product of stage rates
Runs in your browser
10 // Clinical trials

A/B Test Planner

How many visitors before a result is valid?

Power analysis
Runs in your browser
11 // Finance

Channel Portfolio Optimizer

How to split budget across channels, with risk?

Markowitz mean-variance
Runs in your browser
12 // Psychology

Brand Memory Planner

How often to email or post before people forget?

Ebbinghaus forgetting curve, R = e^(-t/S)
Runs in your browser
13 // Finance

SEO vs Paid Breakeven

When does content beat ads on cost?

Compounding asset vs decaying spend
Runs in your browser
14 // Military strategy

Share of Voice Planner

How much spend to take share from a bigger rival?

Lanchester's square law, ESOV
Runs in your browser
15 // Psychophysics

Price Increase Tester

How much can price rise before buyers notice?

Weber-Fechner just-noticeable difference
Runs in your browser
16 // Tax arithmetic

Ad Spend Tax Calculator

What does an ad budget cost after tax?

GST/HST (Canada) and GST (India) on Google and Meta ads
Runs in your browser

03 // Utility / The everyday math

Seven quick calculators

Accounting

ROAS Calculator

How much revenue does each ad dollar bring back?

ROAS = revenue / ad spend
Runs in your browser
Accounting

Break-Even ROAS Calculator

What ROAS do I need to avoid losing money?

Break-even ROAS = 1 / gross margin
Runs in your browser
Media buying

CPM Calculator

What do I pay per thousand impressions?

CPM = spend / impressions × 1,000
Runs in your browser
Media buying

CPC Calculator

What does each click cost me?

CPC = spend / clicks
Runs in your browser
Media buying

CTR Calculator

What share of viewers click my ad?

CTR = clicks / impressions
Runs in your browser
Finance

CAC Payback Calculator

How many months until a customer pays back their cost?

Payback = CAC / (monthly revenue × gross margin)
Runs in your browser
Accounting

Margin vs Markup Calculator

What is the difference between margin and markup?

Margin = (price - cost) / price; Markup = (price - cost) / cost
Runs in your browser

04 // Principles / The ideas behind the tools

Four principles, one way of working

Information theoryOne surprise, a thousand confirmationsClaude Shannon defined information as surprise: an expected message carries none. You need one surprise to be noticed, then consistent proof of it to be chosen.Evolutionary biologyProof that can't be fakedIn 1975 Amotz Zahavi proposed that animals trust signals that are costly to produce, which is why a peacock's tail proves fitness. Now that AI makes words nearly free, trust moves to working tools, original data and named results.Japanese aestheticsThe pause is part of the messageMa is the Japanese idea of meaningful space between things, like the rest in a piece of music. Always-on brands become noise, so we plan gaps as carefully as messages.PhysicsBuild massIn general relativity, mass curves space, so nearby objects fall toward it. Mentions, citations, original data and clear answers add up until search engines, AI assistants and buyers lean toward a brand.

05 // Questions

About the Growth Lab

Are the calculators free?

Yes. Every Growth Lab tool is free, needs no sign-up, and runs in your browser.

Is anything I type stored?

The calculation runs on your device. We use analytics to see which tools people open, and may record rough ranges, never exact figures or anything that identifies you, to publish anonymous benchmarks.

How accurate are the results?

Each tool uses a published model and shows its formula, so you can check the working. Results are estimates that depend on your inputs; use them as a starting point for a decision, not a guarantee.

Why borrow models from other sciences?

Many marketing problems already have a well-tested model elsewhere: how an idea spreads (epidemiology), how ad effects fade (pharmacokinetics), how fast a queue of leads clears (telecom). Borrowing them means fewer guesses with your budget.