Productivity tools. In your browser.
Every Productivity tool in the Digital Heroes library, client-side, free, no signup. Nothing is uploaded or saved to a server.
A free online tool by Digital HeroesA/B Test Sample Size Calculator
Free A/B test sample size calculator. Per-variation sample from baseline conversion rate + minimum detectable effect + statistical…
Affiliate Commission Calculator
Free affiliate commission calculator. Per-sale + monthly net (after fees), tier-bonus targets, recurring SaaS lifetime. Flat / tiered /…
Age Calculator
Your exact age in years, months & days — plus next-birthday countdown and the day you were born.
AOV Calculator
Free AOV calculator. Compute average order value, CM per order, channel AOV, and simulate revenue lift from +$5 to +$25 AOV scenarios.…
Aspect Ratio Calculator
Solve width/height for any aspect ratio, with screen & video presets.
Blended CAC Calculator
Free blended CAC calculator past Meta vendor dashboards. Sum paid, organic, tools, fees; divide by new customers. True acquisition cost…
BMI & Calorie Calculator
BMI, BMR and daily calorie needs (TDEE) — metric & imperial.
Bounce Rate Calculator
Free Shopify bounce rate calculator. Single-page-session %, DTC / blog / B2B / SaaS benchmarks, conversion-lift simulator from a 5-20pp…
Break-Even Calculator
Free break-even calculator. Compute break-even units, revenue, contribution margin, margin of safety, and days from fixed cost per unit…
Break-Even ROAS Calculator
Free break-even ROAS calculator. Minimum ROAS to break even from contribution margin. Refund-adjusted floor + LTV-aware target.…
Budget Planner (50/30/20)
Build a 50/30/20 budget from your income — customizable categories with a visual split.
Burn Multiple SaaS Calculator
Free burn multiple SaaS calculator. Net burn / net new ARR per the David Sacks framework. SaaS verdict tiers + cash-runway sanity…
Calorie Calculator
Daily calories (BMR & TDEE) with activity levels, goals & macro split — Mifflin-St Jeor.
Chart Maker
Paste data and get a clean bar, line, pie or donut chart — export PNG.
Churn Rate SaaS Calculator
Free churn rate percent calculator for SaaS. Compute logo churn percent, revenue churn, net revenue retention (NRR), annualized churn…
SaaS Cohort Retention Calculator
Free cohort retention calculator. 24-month survivor curve + half-life from monthly retention rate. SaaS / DTC / mobile presets.…
Compound Interest Calculator
Project savings & investment growth with contributions and a year-by-year chart.
Conversion Funnel + CVR Calculator
Free 5-stage conversion funnel calculator. Identifies leakiest stage by benchmark gap, projects revenue from a +5pp fix. DTC / SaaS /…
Conversion Rate Calculator
Free conversion rate percent calculator with visitors lift. Compute CVR, revenue per visitor, category benchmark, incremental-revenue…
Countdown & Stopwatch
A big countdown timer and stopwatch with alerts — for events & focus.
CTR Calculator
Free CTR organic position clicks calculator with 9 channel benchmarks (Google, Meta, Display, TikTok, LinkedIn, email, organic SERP).…
Currency Converter
Convert between 150+ currencies with editable offline rates (optional live update).
Date Calculator
Days between dates, add/subtract time, age & business-day counts.
DAU MAU Users + SaaS Ratio Calculator
Free DAU/MAU users stickiness calculator. 7 category benchmarks (messaging, social, productivity, B2B SaaS, ecommerce). Habit-tier…
Decision Matrix
Score options against weighted criteria to find the best choice — saved locally.
Decision Maker
Can’t decide? Spin a wheel, pick a name, flip a coin or roll dice.
Profit + Percent Calculator
Free ecommerce profit calculator. Enter revenue, COGS, shipping, fees, ads, fixed costs. Get gross margin percent, contribution margin,…
Eisenhower Matrix
Prioritize tasks in urgent/important quadrants — drag between boxes, saved locally.
Email Monthly List Growth + Churn Calculator
Free email list growth calculator. Projects subscribers over 12-24 mo from starting list, signup %, churn %. Target line + horizon…
Event Countdown
Live countdowns to your big dates — exams, launches, weddings — multiple events, saved locally.
Expense Tracker
Log income & expenses by category with totals and a chart — private, export CSV.
Flashcards
Create study decks and review with flip cards & spaced repetition — local.
Fuel Cost Calculator
Trip fuel cost from distance, mileage & fuel price — round trips, cost split between passengers.
Gantt Chart
Plan a project timeline with tasks and a visual Gantt — export PNG.
Goals & OKR Tracker
Free OKR tracker: objectives with measurable key results, auto progress rollups, overall score, on-track / at-risk flags. Browser-only.
GPA Calculator
Calculate weighted GPA from your courses, credits & grades.
Grade Calculator
Weighted course grades & “what do I need on the final?†— categories, weights, targets.
Habit Tracker
Build streaks with a clean habit grid — stored locally, never uploaded.
Headline Analyzer
Free headline analyzer. Score blog headlines 0-100 on length, word mix, emotion, power words, clarity, and SERP meta fit. For ad,…
Calendar Event (.ics)
Create an event and download a .ics for Google, Outlook & Apple Calendar.
Invoice Generator
Create branded invoices with your logo and export to PDF — all free.
Kanban Board
A private kanban that saves to your browser. Export/import JSON.
Loan & EMI Calculator
EMI, total interest & a full amortization schedule for any loan or mortgage.
LTV Calculator
Free LTV calculator. Enter AOV, purchase frequency, customer lifespan, and gross margin. Get gross LTV, contribution LTV, and CAC…
Markup Calculator
Free markup calculator. Bidirectional entry (markup percent, margin percent, or selling price). Industry benchmarks. Markup vs margin…
Math Practice
Timed arithmetic drills — choose operations & ranges, track accuracy and personal bests.
Weekly Meal Planner
Plan a week of meals on a grid and auto-build the grocery list — saved locally.
Meeting Cost Calculator
See what a meeting really costs — attendees × salary × time, live.
Mind Map
Brainstorm on an interactive mind map — add, drag, color & collapse nodes, export PNG/JSON.
MRR ARR Calculator
Free SaaS MRR + ARR development calculator. Compute monthly recurring revenue, annualized ARR, net new MRR, growth rate, Quick Ratio…
Notes
A fast local notebook with Markdown — stays on your device.
CAC Payback Calculator
Free CAC payback calculator with contribution margin. Enter AOV, repeat rate, gross margin, CAC. Get months to payback, cohort…
Percentage Calculator
Percentages, % change, discounts and tax/VAT — all in one place.
Periodic Table
Interactive periodic table — search elements, view properties, categories & trends.
Pomodoro Timer
Focus timer with task list and session stats.
Portfolio Maker
Build a portfolio, CV or resume website from a simple form — 3 themes, live preview, one-file export ready for GitHub Pages.
Project Board
A beautiful Asana-style board — labels, assignees, due dates, subtasks & drag-drop. Saves locally.
Random Number Generator
Cryptographically random numbers — ranges, count, unique mode, sorting, lottery & dice presets.
Resume Builder
Fill in your details and export a clean, ATS-friendly resume PDF — saved locally.
ROAS Calculator
Free ROAS calculator. Compute per-channel ROAS across Meta, Google, TikTok, and affiliate. Get blended ROAS and break-even ROAS from…
Runway Calculator
Free startup runway calculator with cash scenarios. Enter cash on hand, monthly burn, monthly revenue — live runway in months +…
SaaS LTV:CAC Ratio Calculator
Free SaaS LTV:CAC ratio calculator with monthly churn. Lifetime value, customer acquisition cost, payback period, ratio + verdict band…
SaaS Magic Number Calculator
Free SaaS magic number calculator. Sales efficiency from new quarter ARR + S&M spend. Verdict bands at 0.5 / 0.75 / 1.0.…
SaaS Quick Ratio Calculator
Free SaaS Quick Ratio MRR calculator. (New + Expansion MRR) / (Churned + Contraction). Stage churn verdict for seed, Series A/B/C,…
Salary Converter
Convert pay between hourly, daily, weekly, monthly & annual — custom hours and weeks.
Scientific Calculator
A full scientific calculator with functions, memory & history.
Shopify ROI Calculator
Free Shopify rebuild ROI calculator. Enter GMV, conversion lift percent, AOV lift, build cost. Get payback month, 12-month return, and…
Shopify Speed Score Test
Free Shopify speed test with score. PageSpeed data, Shopify apps detection (Klaviyo, Yotpo, Judge.me), Core Web Vitals, per-app weight…
Sleep Calculator
Find the best bedtime or wake-up time using 90-minute sleep cycles.
Spreadsheet
A mini spreadsheet with formulas (=SUM, =A1*B2…) and CSV import/export — runs locally.
A/B Test Statistical Significance Calculator
Free A/B test significance calculator. Control + variant lift, two-proportion z-test, p-value, confidence, lift %. Verdict at 90/95/99%…
Statistics Calculator
Paste numbers for mean, median, mode, std-dev, quartiles & a histogram.
Subscription Tracker
Track recurring subscriptions and see monthly & yearly totals — saved locally.
Random Team Generator
Split a list of names into fair random groups or pairs — perfect for classrooms & teams.
Day Planner (Time Blocking)
Plan your day in time blocks on a visual schedule — saved locally.
Time Card Calculator
Add up clock in/out times & breaks for daily/weekly hours, overtime & pay.
Time Zone Converter
Convert any date & time between time zones — DST-aware, with copy-ready results.
Time Zone Planner
Find the best meeting time across multiple time zones.
Tip & Bill Splitter
Split a bill with tip across any number of people, instantly.
To-Do List
A fast daily checklist that saves to your browser — priorities, due dates, drag to reorder.
Typing Speed Test
Measure your typing speed (WPM) and accuracy with timed tests — saved locally.
Unit Converter
Convert length, weight, temperature, area, data & more.
UTM Builder
Free UTM builder. Tag paid campaign URLs with UTM parameters. Platform presets for Meta, Google, TikTok, LinkedIn, Email, Klaviyo. QR…
Whiteboard
An infinite canvas to sketch, add shapes, text & sticky notes — export PNG.
World Clock
Track the current time across multiple cities and time zones at a glance.
