Yes, for most everyday amounts you can take calcium and magnesium at the same time. Plenty of people do, and plenty of products combine them in one tablet. Some people space them apart, and it helps to know why so you can decide what suits your routine.
Together is common, spacing is optional
If manufacturers put both minerals in a single tablet, taking them together is clearly a normal choice. The reason some people separate them is that minerals can compete for absorption when the amounts are large. The body takes up different minerals through some of the same pathways, so a very high amount of one can, in theory, affect how much of another gets absorbed at that moment. That's a general pattern, not a strict rule.
At everyday amounts, taking both with the same meal keeps things simple, and simple routines are the ones people keep. Anyone who has tried to juggle three or four supplement times a day knows how fast that falls apart, often by the second week. A schedule you can actually follow beats a perfectly optimized one you drop.
That said, "usually fine together" doesn't mean the same answer for everyone. Some people take calcium for bone health and magnesium for sleep or muscle comfort. In that case the best timing might just be whenever each is easiest to remember, or easiest on your stomach.
Making minerals part of your day
If you do decide to space them, a reminder for each time takes the effort out of it. Pillog lets you set separate times, check each one off from the notification, and see your month as a card, all on your phone with no account and no ads. You don't have to keep "morning calcium, evening magnesium" in your head. You just tap.
The right amounts and combinations depend on your diet, so your doctor or pharmacist is the best guide. What works for a friend, or what you read online, may not fit your diet, your other supplements, or your medications. Use general information like this to start that conversation, not to end it.
Building a routine that actually sticks
A lot of people start with a new bottle of each and a plan to take them "properly spaced." Then a busy week comes along and the plan quietly disappears. Start small. Pick a time of day that's already tied to something you never skip, like brushing your teeth or making coffee, and attach the supplement to that.
If you want some separation, a pattern many people land on is calcium earlier in the day and magnesium in the evening, since magnesium often gets paired with winding down. That's about convenience, not a requirement, so change it to fit your day. A routine you're still following in three months is worth more than an ideal one you quit after a week.
Give yourself some time to find what works. One combination might sit better with your stomach than another, or taking them with food might feel more comfortable than on an empty stomach. Small adjustments like that are normal. If something doesn't feel right, check in with a pharmacist instead of pushing through.