Everything on this page is a real optimization model with a real solver behind it, running in your browser for free. No signup, no trial clock, no card on file, no “contact sales.” I spent twenty-plus years building these models in Excel for companies that paid serious money for them — Cargill, Cessna, Textron — and they all ended up trapped in spreadsheets nobody but me could open. These are those models, one at a time, turned into something anyone can use.
Each one is honest about what it does not do, which is the part most tool pages skip. Start with whichever problem sounds like yours.
Vehicle route optimizer
Given a list of stops, a set of vehicles, and your real constraints, it decides which vehicle visits which stop and in what order. It handles time windows (this customer only takes deliveries 9–11), vehicle capacity (up to three separate capacities — weight, volume, pallets), service time per stop, and real road drive times pulled from OSRM rather than straight-line guesses. The solver is Google OR-Tools running a guided local search. The sample workbook routes 113 stops across 10 vehicles.
What it doesn’t do: live re-optimization during the day, driver apps, or proof of delivery. It solves the routing math; it isn’t a dispatch platform. It also reads its own workbook layout, not any spreadsheet you happen to have — download the sample and paste your stops into it.
Open the route optimizer — or read what the vehicle routing problem actually is first. There’s also a Spanish version.
Staff scheduler
Three different tools that share an engine. Slot scheduling builds shifts inside a single day to match a demand curve — right for call centres, restaurants and shops where coverage needs change hour to hour. Shift scheduling is a 24/7 cross-day model for operations that never close, with pages tuned to specific settings: nursing, police, security, call centres and others. Rotation generators produce fixed repeating patterns — DuPont, Panama, Pitman, 4 on 4 off — which is a calendar problem, not an optimization one.
What it doesn’t do: time clocks, payroll, or shift swapping. It produces the roster; running it day to day is someone else’s software.
Project scheduler and Gantt chart
A resource-constrained project scheduler. You give it tasks, durations, dependencies and the crews available; it finds the schedule, computes the critical path when crews are the binding constraint rather than the logic, levels resources so you stop double-booking the same people, and will crash the schedule — buy time with money — if you tell it what overtime costs. It reads and writes Microsoft Project XML, so a plan can go out to Project and come back.
What it doesn’t do: cost tracking, earned value, or multi-project portfolios. The shipped template tops out around 60 tasks.
Open the project scheduler, or grab the free Gantt chart Excel template.
Roth conversion calculator
This one is aimed squarely at early retirees. It doesn’t ask “should I convert this year” — it optimizes the whole conversion and drawdown horizon at once to minimize lifetime tax, which is a genuinely different question and one you can’t answer year by year. It models real graduated state brackets (not a flat rate), long- and short-term capital gains on a brokerage account, paying the tax bill from your own accounts rather than from thin air, and optionally the two surcharges that bite this audience hardest: IRMAA, correctly treated as a cliff with its two-year lookback, and the 3.8% net investment income tax.
What it doesn’t do yet: ACA premium tax credits, and Social Security taxability is a flat assumption rather than the provisional-income formula. Both matter for pre-65 retirees and both are on the list.
Open the Roth conversion calculator, or read when a Roth conversion actually makes sense.
Daily fantasy lineup optimizers
Lineup construction is a knapsack problem with side constraints, which makes it a perfectly good excuse to point a real solver at something fun. Both take a DraftKings, FanDuel or Yahoo export, build up to 25 lineups, and handle stacking and exposure limits rather than just maximizing projected points one lineup at a time.
MLB lineup optimizer · NFL lineup optimizer
Why these are free
There’s no catch and no business model hiding behind it. I’m semi-retired; this is what I do instead of consulting full time. The models were already built and paid for by twenty years of day jobs, and the marginal cost of letting you run one is a few cents of server time. What I get out of it is that the work is out in the world instead of sitting in a folder.
If you want the long version — how a twenty-year-old Excel model becomes a web app, and what breaks along the way — that’s the series. More about me is on the about page.