Tree Calculator: Free Tree Calculators and Tools

Use our 12 free tree tools to find a tree’s age, trunk size (DBH), height and value, check a tree for warning signs, pick a fast-growing tree, and work out wood, mulch and chainsaw fuel. Each one uses standard arborist methods and works anywhere in the U.S. The permit checker covers Northern Virginia and Washington, DC.

Schedule Online

Call (703) 659-8733

Free, No Sign-Up

ISA Certified Arborists

Free Tools From Our Arborists

Fast. Free. Tree Answers.

Tree Age Calculator

Estimate how old a tree is from its trunk width and type. Yard trees grow faster than forest trees, so you get an age range. Pick from 41 common trees.

Open the Calculator

Tree Diameter Calculator

Find a tree’s trunk diameter at 4.5 feet (DBH) with a tape, a string, or just a ruler from a distance. It works for trees with several stems, too.

Open the Calculator

Tree Height Calculator

Measure how tall a tree is with your phone, the stick trick, the tree’s shadow or a quick guess. The math is shown.

Open the Calculator

Tree Value Calculator

Estimate what a tree is worth with the CTLA trunk formula, the standard arborists use to value trees. It looks at species, size, condition and location.

Open the Calculator

Critical Root Zone Calculator

See how much soil to protect around a tree during construction: 1.5 feet of radius for every inch of trunk width (DBH), adjusted for species and soil.

Open the Calculator

Tree Risk Self-Check

Answer 3 short questions about one tree to see a general, possible risk level and the warning signs to watch. General information only, not an inspection.

Open the Calculator

Tree Symptom Checker

Tell us what you see, like thin leaves, holes or peeling bark, and get possible causes to ask about, simple checks and what to avoid.

Open the Calculator

Fast-Growing Tree Picker

Type your ZIP code to find fast-growing trees for your hardiness zone, sun and space. See how fast they grow, how far to plant them, and which invasive trees to skip.

Open the Calculator

Tree Wood Calculator

Find out how much your tree or log weighs, how much firewood it makes, and how much lumber you could cut from it. Board feet, firewood cords and heat, too.

Open the Calculator

Mulch & Stone Calculator

Find how many cubic yards or bags of mulch, pine straw, gravel or stone you need, plus a cost estimate.

Open the Calculator

Chainsaw Fuel Mix Calculator

See how much 2-stroke oil goes in your gas for 50:1, 40:1, 32:1 or any ratio, in ounces or mL. Always follow your manual.

Open the Calculator

Tree Removal Permit Checker (Northern VA and DC)

See if a tree removal permit is likely needed in 11 Northern Virginia and DC places, which office to call, and the official page. General information, not legal advice.

Open the Calculator

Book Online

Our Customer Testimonials

Grant Brothers Tree Service Reviews

Grant Brothers Tree Service has provided expert tree care for hundreds of homeowners. Our team handles tree removal, pruning, stump grinding, plant health care and land clearing to protect your property and improve your landscape. We provide clear, up-front pricing, competitive rates, and back every project with our exclusive satisfaction guarantee, so you get professional results you can trust.

“I understand now why there are SO MANY 5-star reviews!!! … They prioritized our situation and were very caring, knowledgeable and reassuring during a super-stressful time. …”
— Amy T., Google review

Read all our reviews on Google

Grant Brothers Tree Service crew on a tree job

The Reliable Choice for Tree Care

Grant Brothers Tree Service, based in Virginia, is the trusted choice for expert tree care. We’re highest rated, with 260+ five-star Google reviews, A+ Accredited with the BBB, and a Nextdoor Neighborhood Fave in 2023, 2024 and 2025. We’re licensed and insured for safe, professional tree work on residential and commercial properties, with the right equipment to get your job done safely and efficiently.

Got a number from one of our calculators? Call (703) 659-8733 or book online, and our arborists will check your trees in person. Work with the most trusted experts in tree care.

Let’s Get Started

Grant Brothers founders Stefano and Jonathan

Nationally Certified Tree Experts

Our calculators give you a fast starting point. For the full answer, our team comes to your property, looks at your trees up close, and tells you exactly what they need. That team includes ISA Certified Arborists, TRAQ-qualified tree risk assessors and CTSP-certified safety professionals. Grant Brothers is led by Virginia’s first ATCP-Certified Professional Arborist (#5 in the U.S.), a founding board member of the Association of Tree Care Professionals.

Whether you’re planning construction, worried about an old tree, or just curious what your trees are worth, our team brings 30+ years of combined experience and gives you clear, honest answers. Call (703) 659-8733 or book online with Grant Brothers Tree Service today.

Our Service Areas