Help!!

How would i work out the calorie content of the following receipe - Its a slimming world one that i loved when i was on sw

Fry Light
1 large onion, peeled and chopped
1 medium butternut squash peeled, deseeded and chopped
2 tbsp medium curry paste
1 x 200g can chopped tomatoes, drained but retaining the liquid
Vegetable stock (Vecon and hot water)
100g dried red lentils
Baby spinach

Plus rice!

Thanks!

Use an online calorie calculator (caloriecount.com is a good free one?)- a lot of stuff is American but you can guess-timate most foods. HTH?