Disclaimer: CoinTracker is provided for informational purposes only. This service is not intended to substitute for tax, audit, accounting, investment, financial, nor legal advice. For financial, tax, or legal advice please consult your own professional. The information on CoinTracker is subject to change without notice. All information is provided "as is." CoinTracker disclaims any responsibility for the accuracy or adequacy of any positions taken by you in your tax returns. Please see our full disclaimer.
You can extend your filing deadline easily and for no extra fee by completing Form 4868. Note that this does not extend your payment deadline, only your filing deadline, so you will still need to pay at least 90% of your final tax bill to avoid fees.
You can estimate your taxes owed using a tool like Tax Caster and the tax summary information on the Tax page. You can submit payment for estimated taxes owed (if applicable) through the IRS website (Reason for payment: extension, Apply payment to: 4868, Tax Period for Payment: 2018).