April 15 is 12 days away. Whether you are filing your 2025 return, calculating Q1 2026 estimated payments, or figuring out how much of your side hustle income goes to the IRS, you need numbers fast.
These five Chrome extensions give you instant tax calculations without leaving your browser. All are free, all use 2026 tax brackets (updated for the OBBBA permanent rates), and none require a signup or send your data anywhere.
Best for: Full-time freelancers and independent contractors with 1099 income.
Calculates your quarterly estimated tax payment including both federal income tax and self-employment tax (15.3% SECA). Enter your projected annual income, filing status, and state — get your exact quarterly payment amount in seconds.
The free tier handles single-income federal + SE tax. PRO adds state taxes, W-2 stacking (for people with both a day job and freelance work), and detailed quarterly payment schedules.
Install Freelancer Tax Estimator
Best for: People with a W-2 job plus side income from gigs, reselling, content creation, or consulting.
The difference between this and the Freelancer Tax Estimator: this tool is designed for people whose side hustle is secondary income. Enter your W-2 salary, then add your side hustle revenue. It calculates the additional tax on your side income — including the SE tax that catches most side hustlers off guard.
If you earned money from DoorDash, Etsy, tutoring, freelance writing, or any other gig in Q1 2026, your first estimated payment is due April 15.
Install Side Hustle Tax Calculator
Best for: W-2 employees who want to verify their paycheck withholding or evaluate a raise, bonus, or job offer.
Enter your gross salary, pay frequency, filing status, and state. See your take-home pay broken down: federal income tax, Social Security (6.2%), Medicare (1.45% plus 0.9% Additional Medicare Tax above $200K), and state income tax. All 50 states included.
Useful right now if you are checking whether your 2026 W-4 withholding is correct. If you owed money on your 2025 return, your withholding may need adjustment before the next paycheck.
Install Paycheck Tax Calculator
Best for: Anyone planning for retirement who wants to model savings growth, Social Security income, and withdrawal scenarios.
Enter your current savings, annual contribution, expected return, and retirement age. The calculator projects your portfolio balance at retirement and estimates monthly income including a Social Security estimate based on your earnings. Adjustable for inflation and different withdrawal rates.
Pair this with a full Monte Carlo simulation for a probability-based retirement plan rather than a single-line projection.
Install Retirement Savings Calculator
Best for: Investors selling stocks, ETFs, crypto, or real estate who need to know their after-tax proceeds.
Enter your purchase price, sale price, holding period, and filing status. Get your federal capital gains tax (0%, 15%, or 20% long-term; ordinary rates for short-term), Net Investment Income Tax (3.8% NIIT for high earners), and state capital gains tax. All 50 states included.
If you are doing tax-loss harvesting or planning year-end sales, this gives you the exact tax impact before you execute.
Install Capital Gains Tax Calculator
Three reasons:
With 12 days left, here is what you should calculate now:
All five extensions are free. PRO upgrades ($4.99 each) unlock state taxes, multi-income stacking, and detailed breakdowns — but the free tier handles the basics for most people.
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