Grant's Tools Professional Calculators

⭐ Go Pro — $5/mo

⚓ Built by an Engineer. For Operators.

Tools That Work as Hard
as You Do

Professional-grade calculators for real estate investors, trucking operators, manufacturing engineers, and machinists — free, fast, and built from real industry experience.

8+Tools & Counting

FreeNo signup needed

Pro$5/mo for the full suite

🏠 Real Estate Tools

Underwrite deals in minutes — not hours. From duplex to multi-family.

Rental Property Cash Flow Analyzer

Full deal analysis for duplexes, triplexes, 4-plexes, 8-units, and custom multi-family. NOI, cap rate, cash-on-cash, GRM, and instant deal verdict.

BRRRR Strategy Calculator

Model your Buy, Rehab, Rent, Refinance, Repeat deals. Calculate after-repair value, refinance proceeds, and leftover equity.

Mortgage Comparison Tool

Compare fixed vs. ARM, 15 vs. 30-year, and different down payment scenarios side-by-side with total interest paid.

🚛 Trucking & Logistics

Know your numbers before you roll. Rate, cost, and profit — per mile.

Load Profitability Calculator

Enter rate, miles, fuel cost, driver pay, and fixed costs. Get instant profit-per-load, CPM, and net margin on any freight lane.

Fuel Cost & MPG Analyzer

Calculate total fuel spend per route. Compare diesel prices, MPG, and reefer fuel. Build your cost-per-mile baseline for accurate bidding.

Owner-Operator P&L Builder

Monthly income vs. expense breakdown for owner-operators. Factor in lease payments, insurance, factoring fees, and maintenance reserves.

🏭 Manufacturing & OEE

Shop floor metrics that move the needle. Built by a manufacturing engineer.

OEE Calculator & Dashboard

Calculate Overall Equipment Effectiveness from Availability, Performance, and Quality. Instant A×P×Q breakdown with shift-level tracking.

Cycle Time & Takt Time Calculator

Find your takt time from customer demand, compare to cycle time, and identify capacity gaps before they become line stoppages.

CAPEX ROI & Payback Analyzer

Justify capital equipment purchases with payback period, NPV, and IRR. Built for engineering project approvals and spend justification.

⚙️ Machining & Tooling

Speeds, feeds, and costs — calculated correctly, every time.

Speeds & Feeds Calculator

Calculate optimal RPM, feed rate, and depth of cut for turning, milling, and drilling. Select material and tooling type for instant cutting parameters.

Part Cost Estimator

Estimate machined part cost from cycle time, material cost, machine rate, and scrap rate. Export quotes in seconds for RFQ responses.

Tolerance Stack-Up Calculator

Perform worst-case and RSS tolerance analysis on multi-component assemblies. Catch fit issues before they reach the floor.

Unlock Grant's Tools Pro

One subscription unlocks premium features across every tool on this site — PDF exports, 5-year projections, deal scoring, sensitivity tables, saved deals, and an ad-free experience. Built for serious operators.

PDF exports

5-yr projections

Deal scoring

Save 20 deals

Sensitivity tables

Ad-free

DSCR metrics

Portfolio view

Priority support

⭐ Start Pro — $5/mo Browse Free Tools →

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👷

Built by Grant — Engineer, MBA Candidate, Investor

I'm a manufacturing engineer with a Finance MBA background, building real estate and trucking side businesses from Michigan. I built Grant's Tools because I was tired of generic calculators that don't reflect how operators actually think. Every tool here came from a real problem I was trying to solve — on the shop floor, in a deal analysis, or behind the wheel.

Manufacturing Engineering Finance MBA Real Estate Investor Trucking Michigan