Business math · for the rest of us

Numbers, finally on your side.

Profit. Tax. Margin. ROI. Currency. The math your business actually needs — calculated instantly, saved automatically, ready to share. No spreadsheets. No "enterprise FP&A platform."

31 currencies · 7 tax regions · Built for makers · Runs in your browser
06 calculators · one workspace

The math your business actually does

Each tool is a single screen. No setup, no schema, no "connect your data source." Type the numbers. Read the answer.

F-01

Profit calculator

Revenue minus everything. Margin, breakdown, projections — all on one screen. Toggle gross vs net, monthly vs annual, with or without taxes.

7cost categories·12moprojection
F-02

Tax calculator

VAT, sales tax, GST — country-aware rates that stay current. Net to gross, gross to net, or a clean line-by-line breakdown for your invoice.

31regions·autorate sync
F-03

ROI calculator

Investment in. Return out. Period and discount rate optional. We chart your break-even point and tell you the exact month you cross it.

IRR+ NPV·break-evenhighlighted
F-04

Currency converter

30+ currencies on mid-market rates. Toggle to bank-spread or your custom rate. Every conversion is dated and saved to history — so you can prove the rate later.

31currencies·mid-marketdefault
F-05

Saved scenarios

Compare what-if-we-hire, what-if-recession, and your base case side-by-side. Tag them. Pin them. Diff them. Never lose a calculation.

unlimitedsaves·3-upcompare
F-06

Audit trail

Who changed what, when, and from what. Every input is timestamped. Restore any previous state in one click. Your accountant will love you.

↑žhistory·1-clickrestore
live · interactive

See it calculate

An actual BlinkCalc profit screen, embedded right here. Change a number — watch every other number react.

SESSION · profit-calc · live
profit=revenue(cost + ads + employees + tax)
USD
USD
USD
USD
Tax estimated at 21% on pre-tax profit · adjust region in app
Pre-tax profit
revenue − costs
$27,100
Tax estimate · 21%
on positive pre-tax profit
$5,691
Net profit · monthly
what actually lands in the bank
$21,409
Net margin
healthy · above 20% target
25.3%
last edit just now · 4 inputs · 4 outputs · $256,908/yr projected
under the hood

How BlinkCalc thinks

Three steps. The same three steps your accountant takes — only the keystrokes are yours and the spreadsheet doesn't exist.

01
Inputs
Type the four numbers you actually know. We default the rest from your region.
revenue 84,500
cost 32,400
ads 6,800
payroll 18,200
02
Formula
A transparent equation. Not a black box. Click any variable to swap in your own rate or region.
subtract costs
apply tax rate
annualize ×12
project 12mo
03
Insights
Net profit, margin band, projection, breakdown — every result with a link back to its formula.
net profit 21,409
margin 25.3%
annual 256,908
breakeven mo 4
profit = revenue (cost + ads + employees + tax)
who's calculating

Built for people who hate spreadsheets

Not for FP&A teams with a Bloomberg subscription. For the actual humans running the business.

USE-01 · retail

Shop owners

Know your real profit on every product, not just gross sales. See which SKU pays your rent and which one is quietly bleeding margin.

margin per SKU · landed cost · weekly net typical setup time · under 4 minutes
USE-02 · services

Freelancers & consultants

Set your rate. See your real hourly after tax, software, and that "quick" admin you never bill for. Adjust before sending the quote.

effective rate · quote builder · tax-aware typical scenario · "is this project worth it?"
USE-03 · small teams

Small finance teams

Model "what if we hire" or "what if revenue drops 20%". Save it. Share it. Compare three scenarios in one view, board-ready.

3-up scenario diff · share link · CSV out typical user · founder + part-time CFO
a saved scenario, expanded

What you get when you save

Not just numbers — a snapshot. Everything that went into the calculation, frozen in time, with a paper trail.

Q4 · what-if we hire 2 designers
last modified May 12 · 14:08 UTC · by @maya · v.3
what-if hiring Q4-2026 design
revenue$92,000
cost of goods$33,800
ads$7,200
payroll (+2)$28,400
tax rate21.0%
regionUS-DE
$17,066
net monthly · margin 18.5% · annualized $204,792
net profit · projection $204,792 annual
14:08:42 @maya changed payroll 24,000 → 28,400
14:04:11 @maya added tags hiring, design
13:58:02 @dan duplicated from Q4 · base case
May 11 @dan created scenario
scenario-id · scn_8f4c2e1b
geo · taxes · currencies

Built for international small businesses

Tax rules and FX rates we actively maintain. If you sell across borders, the math doesn't break at the border.

US sales tax UK VAT DE EU VAT IL VAT (Ma'am) CA GST + PST AU GST SG GST FR TVA ES IVA IT IVA NL BTW IE VAT SE Moms CH MWST JP CT IN GST + 15 more →

FX rates refreshed every 60 seconds · tax rules versioned with effective dates · all jurisdictions reviewed quarterly

interop · the rest of the stack

BlinkCalc plays well with your tools

Pipe in cost-per-customer from Crewix. Pull margin-per-product from PopCart. Drop in campaign ROI from Flowly. Or just import a CSV and walk away.

CX
Crewix
cost per customer · CAC sync
PC
PopCart
margin per product · SKU feed
FL
Flowly
campaign ROI · attribution
.c
CSV in/out
drag · drop · done
$
Stripe sync
revenue, fees, refunds → BlinkCalc
soon
FAQ · the four we get most

Reasonable questions, direct answers

Q-01 Are tax rates up to date?
Yes. We pull standard VAT, GST, and sales-tax rates from official jurisdiction sources and review them quarterly. Each rate is stamped with an effective date — so if a calculation was made under an old rate, you can see it in the audit trail. For US state and local sales tax, we cover state-level rates; local overrides can be entered manually per scenario.
Q-02 Can I share a scenario with my accountant?
Yes. Every scenario has a "Share" action that generates a read-only link. Your accountant doesn't need an account to view inputs, results, the formula, and the audit trail. You can revoke the link any time, and shares are logged with view timestamps.
Q-03 Does it support my country's VAT?
We ship native rules for 31 regions including the US, UK, EU member states, Israel, Canada, Australia, Singapore, Japan, and India. If your country isn't natively supported you can still calculate manually — enter your own rate, label it, and BlinkCalc treats it as a first-class jurisdiction inside your account.
Q-04 What if my numbers are sensitive?
Calculations run in your browser — nothing leaves your device unless you save a scenario, and even then it's encrypted at rest. We never train models on your financial inputs. You can enforce SSO, set data residency (US/EU), and export every scrap of your data on demand.
the N.T.J ecosystem

Other tools from N.T.J

Same design language. Same vibe. Different jobs.

ready when you are

Stop opening that spreadsheet.

Two minutes from now you'll have a saved scenario, your margin in writing, and a fresh respect for your own numbers.

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Scenario saved. scn_····