I want to tell you about a retirement calculator I tried called OnTrajectory. It’s a detailed simulator that asks for a lot of inputs and then shows a timeline of where your money will be by age 90 (or any end age you pick).
At first I was skeptical. I’m a spreadsheet person—I like controlling every cell and formula. But OnTrajectory gets you started quickly. Right away it asks for basic info, and after you enter that you get a trajectory line showing your projected balance at age 90. Pretty neat. The tool factors in lots of variables.
After about 45 minutes of easy data entry, here’s what our trajectory looked like.
OnTrajectory creates a “Deposit Account” for your net income (future savings after expenses). I like that it uses this to estimate your effective tax rate. That matters because if you plan to retire early you’ll want to know whether you’ll qualify for health care subsidies and what your future tax bills might look like.
You can set age ranges and use a “Growth Override” to plan changes in income—for example, telling the simulator when your job income stops at early retirement. You can also set predicted raises by adjusting percentage growth year by year. Those features are handy; it’s not easy to do that in Excel without extra tabs or complex macros.
Entering expenses is simple: just enter your current average monthly total. The cool part is modeling future changes by adding a new expense line with an age range. That’s useful for early-retirement planning since monthly costs change as mortgages get paid off or kids leave home.
Since I love spreadsheets, I used the data view to watch how the numbers grow over time. You can also switch to “tomorrow’s dollars” to see the effect of inflation.
The simulator makes some assumptions that don’t jump out until you dig into the data. For example, I saw a couple of big spikes in our 401(k) on the graphs. The data table showed that OnTrajectory assumes proceeds from selling your home or rental properties go straight into a 401(k)-like IRA/retirement account—that’s the Deposit Account I mentioned. I like that; we’ll probably put sale proceeds into Vanguard anyway.
I did run into some issues while writing this review. The first time I entered all my income info the site froze and I lost everything—about 15 minutes of work. Not a huge deal, but annoying. I use Chrome on Windows 10 and a well-kept machine, so I was surprised.
Tyson Koska, OnTrajectory’s founder and CEO, was very responsive. Since that initial glitch I haven’t had further problems. There’s an autosave feature that keeps your info as you go; in my case the outage was due to a hosting patch being applied early on a Saturday morning.
There’s a minor bug where the tutorial pop-up can get stuck if you drag it too high so its header can’t be clicked. I did this a couple of times and had to restart my session, but autosave did its job, so I didn’t have to re-enter everything. Lesson learned: don’t move the tutorial popup—just read it, close it, and carry on.
OnTrajectory has a free plan and a PowerPlan for $5 per month. Full disclosure: I was given PowerPlan access to write this review. I’m not shy about calling out flaws. Try the free plan first to see if it fits you. After using PowerPlan for a few days, I think it’s a great complement to my spreadsheets.
I like OnTrajectory. What stands out is the attention to detail and the range of levers you can pull for early-retirement planning. I wasn’t sure how it would handle real estate, but it does a solid job accounting for appreciation, equity, and discounts at sale.
The interface is clean. One suggestion: they could simplify data entry with a decision-tree style input like TurboTax uses—this would help users who are intimidated by a lot of manual entries.
What do you think? Is OnTrajectory the tool you’ve been looking for? Try it and share your thoughts.
Tyson replied the same day I posted this review. His team plans to fix the tutorial popup bug this coming weekend—true agile development for the software nerds out there.