With your Heard subscription, you can expect to receive your quarterly estimates once you complete your quarterly checklist. If you missed the deadline to submit the quarterly tax checklist, or it’s now past the IRS payment deadline, you can use the Heard Quarterly Tax Safe Harbor Calculator to calculate the minimum amount to pay the IRS for 2026 quarterly taxes to avoid an underpayment penalty.
It applies either 100% or 110% of prior-year federal taxes, depending on income, and is split into four equal quarterly payments.
Before you start: what you'll need
Have the following available from your 2025 Form 1040 before opening the calculator:
- Line 11 — prior year Adjusted Gross Income (AGI)
- Line 24 — prior year total federal tax
💡 Tip: If Heard filed your taxes, your 2025 Form 1040 is accessible in your Tax Documents.
How to complete the calculator
Go to https://www.joinheard.com/heard-member-safe-harbor-calculator-quarterly-tax-estimates
- Select your filing status from the dropdown. This sets the AGI threshold — $150,000 for most filers, $75,000 if Married Filing Separately.
- Enter prior year AGI (Line 11). This determines whether the 100% or 110% safe harbor rate applies.
- Enter prior year total federal tax (Line 24). Total tax owed for 2025 — not the refund, not what was paid at filing.
- Toggle on Include state estimated taxes to see a combined federal and state estimate, or leave off for federal only.
- Review results for the quarterly payment amount and annual safe harbor total.
What to do next
After reviewing the safe harbor estimate:
- Make your federal quarterly payment by logging in to your IRS account. For more, see How to pay federal quarterly tax estimates
- Pay state estimated taxes by logging in to your state's department of revenue account. For more, see Paying Quarterly Tax Estimates by State
- Mark as paid in Heard, log your payment in Taxes>Quarterly, see How to enter quarterly tax payments in Heard
How this calculator differs from your Heard estimate
Heard's quarterly estimate is based on your actual income data — projected business profits, W-2 income, and withholdings on file. For more, see How does Heard calculate quarterly estimated taxes?
This calculator uses a different method: it applies the IRS safe harbor rule to last year's tax data to show the minimum payment that protects against underpayment penalties.