The various websites do not tend to get the number of bitcoin wrong, so they tend to be pretty close to one another, as you have shown, yet sometimes they do not calculate the BTC spot price value of your BTC holdings correctly, so sometimes it is good to manually verify.. and also sometimes we have to double check the dates, since Samlucky O's earlier version did end up having a mistake in the date, and he was saying that it was for 5 years, yet the date in the search bar and the results ended up being for 4 years rather than for 5 years.
Sometimes, the difference end up being quite great, so sometimes it is worth it to verify the results so that we might not misstate the points that we might be trying to make, whether we are engaged in historical analysis or if we might be trying to project into the future, and for sure if we are projecting into the future, we can ONLY attempt to do our best, since we don't know the actual prices in the future as we would be able to find out for the past... we also are likely to be dealing with several uncertainties in regards to our own income/expenses/discretionary income and even various factors underlying how we get to those numbers. since the facts are likely to continue to change, and sometimes in very unexpected ways... yet we still should attempt to try our best in terms of attempting to figure out most likely scenario and then various extremes on either end.. and even if we might try to prepare for both the base case scenario and the extremes at the same time, we should attempt to moderate our approach so that it becomes less and less and less likely that we end up getting reckt, even if there might be some scenarios that are more advantageous for our own situation.
Sometimes, the difference end up being quite great, so sometimes it is worth it to verify the results so that we might not misstate the points that we might be trying to make, whether we are engaged in historical analysis or if we might be trying to project into the future, and for sure if we are projecting into the future, we can ONLY attempt to do our best, since we don't know the actual prices in the future as we would be able to find out for the past... we also are likely to be dealing with several uncertainties in regards to our own income/expenses/discretionary income and even various factors underlying how we get to those numbers. since the facts are likely to continue to change, and sometimes in very unexpected ways... yet we still should attempt to try our best in terms of attempting to figure out most likely scenario and then various extremes on either end.. and even if we might try to prepare for both the base case scenario and the extremes at the same time, we should attempt to moderate our approach so that it becomes less and less and less likely that we end up getting reckt, even if there might be some scenarios that are more advantageous for our own situation.
These tools come handy but there is no harm in doing manual calculations to correlate the results or make sure we have 100% correct result at our disposal.
There is another tool https://hodl.camp/ that quickly gives you idea of how much profit you will earn if you HODL for a specific duration. By just moving mouse you can get details. Like I caught the following screen shot that tells if you made entry on Jan 02 2020 when Bitcoin price is $6946 and made an exit on Jan 02 2022 when bitcoin price is $47352, you HODL for 2 years and had a profit of 581% in that two years. I don't get idea about the capital with which entry was made and whether it's lump sum investment or DCA, may be you can throw some light on that.
I am combining all these tools here for future reference.