If you do not know what you will be making as the dollar or pound amount you can still find out the percentage you earned in a salary hike. You can take your current salary and what the new salary will be. For example, if the new salary is 42,000 and you were making 40,000 then you have an increase of 2,000 for your salary. You would then take 2,000 divided by 40,000 to determine the percentage of the salary hike, which is 5 percent.
If you want to know the percentage and you know the pound or dollar amounts of your new pay per hour you can also take those and derive the answer. Again, if you make 10 per hour right now and the new amount is 12 per hour then you would have a difference of 2 per hour. You would take 2 divided by 10 to arrive at the percentage, which is 20 percent of a salary hike.
As long as you know what you were making and what you will be making you can use new minus current= difference in pay divided by current= percentage of salary hike.
For those with an hourly base if you know the percentage the calculation would be hourly rate x percentage= new earning rate per hour.
If you know the hourly rate but not percentages it would be new hourly rate minus currently hourly rate= pay difference divided by current rate= percentage of pay increase.