In all my 25 years of life, I have never been without a dog. As a kid, I always lived with at least two, and had as many as six after my parents, both dog people, divorced and remarried other dog people. When my spouse and I moved in together after I graduated college, we set a rule: We could get a pup once I had found a full-time job and we could properly afford vet care and, of course, food. But figuring out if you're ready to own a dog is about much more than just money.
I wish I could say my spouse and I had a cute or clandestine reason for going from "sometime" to "right now, immediately" when it came to getting a dog, but nope. We were trapped in a one-year lease in a dangerous neighborhood and had recently had a break-in. It was, we decided, dog time. (To be clear, I definitely wouldn't recommend anyone get a dog purely to look out for their house — my spouse and I had already made our decision and were casually on the lookout for pups when we had our break-in.)
Having had very young puppies before, I knew I wanted a slightly older dog. Pre-grown, my spouse joked. But even "pre-grown" dogs will come with huge demands on your time, which is absolutely the first part of readiness you need to consider, even before you think about whether you can afford a dog. That may be a controversial opinion, but the way I see it, there's no point in having a dog you don't have time for, or worse, don't want to make time for. I work from home, so luckily I have plenty of time for a dog, but if you're someone who's away from home 12 hours a day, you have to consider whether you're in a position to give a dog the best home, no matter how much you want one.
You also have to sit down and consider some uncomfortable possibilities about yourself, like why you want a dog in the first place. If you're just looking for companionship but are away from home a lot, a lower-commitment animal may be best. If you're going to get a dog, you're going to have to be prepared for your schedule to radically shift, and that can be far more stressful than anticipated. Make sure you're thinking beyond cuddle time and snoozing together and fun jaunts in the park. Think about the inevitable day when you have a migraine, or are on a deadline, want to take a spontaneous day trip, or just want to sit down and chillax after a long week at work, but you have to take your dog out immediately — and then again at 5 a.m. the next morning.
If you think you can pencil in early morning wake-ups, walks, and just plain bonding time, then you definitely do need to consider financial stability. You'll need to afford set-up supplies like a crate, collar, and leash, plus food on the regular and vet care on the slightly-less regular. It's a good idea to get pet insurance, so get a quote and see if you can afford that too, to help mitigate eventual emergency vet bills.
Dogtime has an excellent "Are you ready?" quiz asking about everything I've mentioned and more, including a weighty first question: "Are you planning to have a baby within your dog's lifetime?" If your answer is "I don't know, maybe," remember that if you're going to get a dog now, you need to be committed to having that dog for the entirety of its life. Getting rid of a dog because you have a kid (or get a new job, or need to move house) is not responsible dog ownership.
Dogtime's quiz also reminds you to think about whether everyone in your family is open to getting a dog, whether anyone is allergic, whether you have a safe yard or walking route, whether you can afford the time and money for thorough socialization and training, and whether you can emotionally and financially handle inevitable damage to your belongings until your new pup is trained.
If you're not ready to take in an animal that is going to change your life, require your attention virtually 24/7, require you to rework your budget, and require you to spend the next 10-plus years putting their needs before yours, then that is totally A-OK. Owning a dog is, in internet speak, A Lot. It's also amazing. Literally nothing in the world compares to a happy dog. And thinking about whether you're truly ready for a full-time commitment to a pup will prepare you to give them the happiest life possible.