My age is 30 my height is 5.1 What should be my weight?

First of all I have some tips for you..!

I suggest you that my humble opinion is that your ideal weight is 98 pounds  to 132.6 pounds, you can calculate your ideal weight through this Weight Loss Calculator.

First start by getting up earlier than usual. Around 5:30 AM to do some of you workouts. Getting up early shocks your metabolism because the body needs more energy to get going. Right? This will start your system on the road to weight loss. That early start with about 10 minutes of stretching. Have a cup of coffee to get the blood going also.

Do all the sit-ups you can. Just do them. 15 or 20 whatever, we don't have a lot of time to work with. Rest 1 minute repeat, do this for 6 sets. Already you are breathing hard and feel worn, because the body is working extra hard at being up earlier and then going right into exercise. If the early morning hour lets you get your cardio in, go ahead and do it. 30 minutes.

Diet. Cut all current meal portions in half, just cut them in half, nothing fancy or complicated, CUT IN HALF! Cut out all bread products, all gravies, candies, chips, night snacks, etc. If you crave at night eat a banana, other fruit or best a non-fat yogurt. There are some tasty ones out there.